Karl Middelhauve is considered the leading expert on the “Grand 600” Mercedes-Benz and the M100 engine in the USA. After a very successful career as an engineer and consultant in the furniture building industry, he continued with his first love – repairing and restoring and modifying the 600 Mercedes and other 6.3 powered cars. He drove Mercedes for years across our country and Europe and loved the comfort, handling and reliability, some years driving over 70,000 miles. The only thing missing was horsepower!
Being German, Karl loved to go fast and feel the torque of a high output motor. At the time (mid to late 60’s) Mercedes only used 6 cyl. motors in their coupes and sedans. That all changed with the introduction of the 600 Model line in 1965 equipped with the mighty 6.3 cu. In. V-8. That engine then made its way into the 300SEL sedan thanks to the efforts of Eric Waxenberg and Rudolph Ulenhault, and the 300SEL 6.3 was born. It also meant 6.3 V-8’s could be swapped into the 300 Coupes and Convertibles which is exactly what Karl did. He was one of the earliest customers of AMG by having a 6.3 conversion done to his 6 cyl. 300SE coupe which blew up on the Autobahn (with Ruth driving).
Karl did several successful conversions with AMG, including this Silver/Red 300SEL Cabriolet 6.3 with a 5sp.manual. (This car is currently for sale in California for $1,000,000)
He then realized that he could do this same work himself and turn his passion into a business. He restored and modified several 300 series cars, even owning a SEL 6.3 Coupe, a 6.3 Convertible and a 6.3 Station wagon all at the same time. He also built the “Hot Benz” black 300SE 6.3 Coupe and installed his own KHM Fuel Injection System.
He then started to focus on the 600 Grand Mercedes. There was real need for a competent, dedicated service and restoration facility and Karl was the man to fill the need. He built his own shop at his home in Woxall, Pennsylvania where he worked on hundreds of cars from simple repair work to full total restorations to custom builds.
Karl in his Woxall, PA Shop 
Karl working on his own design 8-stack Fuel Injection System
Some of his most famous custom creations were:
A 300SEL3.5 with electronic fuel injection and a rear axle mounted turbo 
A 280SE 4spd. With turbo and water injection
A 600 SWB with a rear axle mounted turbo, electronic fuel injection, MSD Ignition and a Tremec 6spd. Transmission (the only know manual shift 600 in the world)
Two 600 based pickup trucks, “Benzamino” and “El Benzo” designed by Paul Bracq 
M-100 group meet Charleston, SC – Paul Bracq Karl Middelhauve discuss design details
A 450SEL 6.9 Pickup named El Benz 
A 600 Coupe made from a sedan to mimic the famous “Nallinger” Coupe
Jay Leno’s famous restored brown 600 with KHM Injection and a supercharger
The 600 “Silver Arrow”-a late model 600SL Silver Arrow edition car with 600 body work
Karl and his wife Ruth hitting the road 
The Grand Mercedes-Benz 600SL
And a 600 based hearse with nitrous injection
Moving to Wausau
During all this success, Karl and Ruth relocated to Wausau, Wisconsin in the early 2000’s and moved their entire business with them.
As recounted by Dave Felten, Karl’s son-in-law, it was quite a project taken on by the family.
“When we moved to Wausau, Wisconsin from Pennsylvania it took six 26′ truck loads to transport our parts. To be more specific, our parts inventory filled thirty-one 72″ steel storage cabinets and 307 banker boxes (24″x10″x14″). We also hauled five M-100 engine cores, five long blocks, one short block, four rebuilt engine heads, eight steering boxes, nine powder coated front axles, nine M-100 rear axles, two 6.3 rear axles, six radiators, eight rebuilt driveshafts, ten transmissions with fluid couplings, forty-two powder coated rims, eight injection pumps and ten cores to name just the more bulky items.
In addition, boxes of cad plating, ten doors, six fuel tanks, front and rear seats, window glass, hydraulic parts, the list goes on and on…some of the many parts collected over the last 40-years.”
We found that during the past 20+ years in his current location the parts stash multiplied exponentially due to Karl parting out 16 to 17 600 sedans and saving every last usable part, nut, and bolt.
Going Into Retirement
Left to right: Our pilot, William Cambell, Dwight Schaubach, and Karl Middelhauve.
Several Years ago, our owner, Dwight Schaubach met Karl and purchased two 600 SWB sedans that Karl had gone through, one belonging to the President of Mexico when new. Mr. Schaubach was also interested in several other cars and discussions were had about additional purchases. Those talks expanded over time into working a deal to purchase the Classic Car Restoration LLC Business including all the remaining cars and its vast parts inventory. Karl was not doing much work anymore and was having some physical challenges that come with hitting the 90-year-old mark so Ruth was very glad that a deal was struck, and Karl could finally slow down and take a rest (not Karl’s choice!).
The planning began with several trips to assess the situation plus months of preparation, then an all-out assault in April 2023 to move everything. A total of five weeks were spent in Wausau, by Neils Schroeder, our Operations Manager and Pat Evans, our Mercedes Specialist culminating in 15 days straight on-site during the actual move. 21 cars and more parts than we even thought was there were packed and moved to our location in Virginia. Due to the restricted access to Karl’s garages, all the cars had to be pulled up to the road and the parts had to be loaded on a separate trailer and moved up to the road and unloaded into the 40’ trailers, transported to Virginia and unloaded again. Maybe 5 of the 21 cars would move under their own power, and the rest had to be towed up to the road where the car carriers were waiting. The 21 cars filled 4 enclosed carriers plus one U-Haul car trailer.
Karl’s Hydraulic Component Test Bench which we moved to Virginia in tact.
Pat Evans, Karl Middelhauve , and Neils Schroeder, and Karl’s hat collection
Karl’s VERY organized workbench and tool wall! 
One of two rooms this same size filled with cars and parts
The parts filled nine loads in 40’ enclosed trailers, three 26’ Ryder truck loads, and a 48’ flatbed trailer. We took all the shelving to be used in our facility, and 4 of the four post lifts which had to be disassembled and banded for shipment.
The first week of the move the weather was perfect, in the 60’s to 70’s and sunny. Then it went downhill fast into the teens with snow and ice. The building heat was not working due to a main boiler issue and plumbing leaks, so we rigged the baseboard heaters to work and bought several small electric heaters and pressed on with the work.
One of the best things every morning was seeing Ruth come across the driveway from the house with a tray of hot coffee, sweet treats, and cookies for us.
Special thanks must go out to Ruth, Karl, their daughter Audrey, and her husband Dave. They were perfect hosts and helped us immensely. Karl would come out for a little while each day and help identify unmarked things in the cabinets and drawers, items only he would recognize or just to watch the slow methodic disappearance of his world in front of him. It must have been very tough to watch!
21 total cabinets were filled like this 
We pre-packed over 90 large totes during previous trips 
Josh and the Speed Transport Crew out of Indianapolis hard at work – They were the best! 
Drawers full of everything you can think of off of a 600 
Clamps …and Clamps… and Clamps (Notice they are cad plated too!) 
More totes – we purchased 70 additional totes once we got there. 
Cabinets had to be emptied , moved to the trailer, then reloaded
Each bin on each shelf in each cabinet was zip lock bagged and marked where it went (as an example 2– A- 3 on a bag would be cabinet 2, shelf A, third bin from the left) and then put back in its same location in the cabinet once loaded in the 40’ trailer. This process was repeated in Virginia when they unloaded everything.
Good thing we brought our utility cart along – carrying bagged cabinet contents up to the road.
The entire attic was full of Doors, hoods, deck lids, glass, seat frames, upholstery, and door panels, etc.. Enough to fill one 40’ trailer load. All of this was put up there by Karl and his son in law Dave.
Door panels 
Deck lids Galore 
Heavy Stuff – Subframes, Driveline parts, steering boxes, engine parts, etc. 
Trailer Load after trailor load moved up to the road for reloading 
Prepping cars for loading 
Car Carriers as far as you can see! Thank you to Tina at Tina’s Transport! 
Rented fork lift saved us – These cars weigh a ton 
Four very nice BMW motorcycles too! 
The really heavy stuff! Differentials, Transmissions, several 4 post lifts, etc. 
Engine Farm – Multiple long block assemblies 
Engine Farm 
Packing grille shells and radiators and fuel tanks 
More and more stuff! 
Karl overseeing the move 
Starting to make a dent!
Finally Clean down to the walls.
Before 
After!
Snowing in Wausau – Beautiful…except we are not done yet!
Trying to stay warm was just as hard as finding a good cell signal! 
Original Cabinets from Karl’s installed in our warehouse in Virginia. 
Heavy duty shelving full up. 
Its all in here, now what do we do? 
The fun has just begun! 
All this plus three Sea Containers full of large items, and half of another warehouse with over 100 wheels and tires, engines, transmissions, differentials, seat frames, and upholstery. It doesn’t seem possible that all this came out of a 100’ x 30’ building that also held 17 cars.
