I have done a 123 box, but never any other MB box. It is indeed different to an American box. What I did was got a wrecking yard box on which I could do exploratory sugery. All the bearings looked good, but there was no way to adjust the end play of the sector bearings. What I did was cut shims from shim stock and got it working pretty darn good.

I have no idea if this approach would work on one of these boxes and you must realize that since there is no adjustment, it is a cut and try procedure for the most part. The 115 boxes had big adjustment nuts on them, so maybe you'll be lucky on your big bodied boxes.

Good luck,