Well, I wasn't aware that I could get original MB motor mounts. The ones I took out were just single piece, must be a very old design, as you can see what I put in matches the workshop manual exactly. I have some troubles here to order parts in general, but I found one reliable supplier in a company called Niemoeller, the price was around 70 EUR per mount. I will definitely keep my eye on them. Part number is D 22 041 (corresponds to MB part 1212230412) from their website. I ordered all the parts for this job from this company, except the bolts which come up from the bottom (MB part 1212200371) which I got from a supplier on ebay, original parts. Plus the hex bolts which I ordered from a bolt company in Scotland.

Any one have a source for OEM parts for these, which will ship internationally? If the ones I got are not OEM?

Yes, I did the pre-tension. It is not so easy to accurately measure the distance "a" as there is an offset between the measuring points, but I felt that 14 mm was too loose, so I actually went to 12 mm. And, yes, I did put a drop of blue lock-tight solution on these bolt threads before tightening. I didn't use lock-tight anywhere else. Once you install the mount, this under bolt is completely hidden, that is why I used the lock-tight, no way to check it after installation.

I would say I have done about 700-800km since the repair, everything looks good so far. Roads are very bumpy here, so I am hoping for the best. Could you be specific on how your mounts failed after 100 miles, maybe I can look out for that?