Yes, whatever happened to my 450SE - yes I did sell it to a guy that lives not far from me. He already had a 450SEL and the idea was for him to dispose of his car as rust was a significant issue. Unfortunately, his purchase of my car did not work out particularly well.
As can be seen from the photographs, I carried out a significant amount of both body and mechanical restoration and, to all intents and purposes, it should have been a good car. I experienced some issues with the engine, and entrusted an unknown to me mechanic to investigate what the problem was likely to be. He had the car for six months, and I have no idea what work he carried out. He eventually advised that he could only turn the engine a certain distance either way, so obviously something seriously had gone wrong with it. I never had that particular problem, therefore further serious investigation became necessary.
Anyhow, he decided to honour his commitment to buy (well, he had already paid for the car - a very reasonable price), and entrusted another mechanic of his choosing to tackle whatever issue prevalent, and eventually (after some two months) removal of the heads revealed a very badly rusted cylinder bore on No. 2 or 3 on the left hand block, ostensibly beyond saving. The last I knew was that he was going to purchase a replacement second hand engine. Unfortunately, from my viewpoint, this transaction turned out to be unsatisfactory for all concerned. Last I knew was that the SEL was still parked outside his home, with no trace of my 450SE. Regards. Styria