Geday from Australia!
My 1987 300D W124 (603 motor - non turbo) has a squeaky belt. There ain't much room to work in the front there, so I have to take off the fan.
For this job it is recommended all over to get a "fan pulley holder" and a short 8mm socket- both Mercedes parts.
Mercedes Australia (specifically Peter in Spare Parts Zetland Sydney in his high handed arrogant fashion) says "I don't sell tools." Wouldn't even listen to the part numbers.

Well bugger them then.
Does anyone know if I can...
a) cut off a 8mm Allen Key (to what length?)

b) for the "holder still-er" there is talk in some places of a piece of thick wire or whatever , bent to L - shape, and put through a hole in the fan pulley and into the block or timing chain cover (sorry not sure) to lock it. Does this work on the 603? Or do I need to clamp it from the circumference of the fan pulley??? If the "bit of wire" works, could someone give me the recipe to make it please?

Thanks in advance for your crazy home made solutions for getting that pesky fan OFF!!! (and back on)