BMW 600 struggled to make a sales impression here, not least for being LHD. So there are not to many of them here. I guess 20 in the UK. Some are USA spec and have been imported over the water. Some get sniffy about that and the stylistic changes. One UK one is, I believe, still listed as stolen - John Dobb, of Telford. I think that one was two tone grey, or some such. So take care its not that one, If it is possible, report it. There are others out there and I am sure the finder would be aided to another car to buy for his due diligence. Good luck with it.
I still have some spare glass screens for a BMW 600.