When you buy an older BMW /2 be sure to check out the numbers. The numbers need to match on the frame, the engine and on the data place fixed to the front of the frame head. The data plate is reproduced so look it over good. I purchased an R50 a few years ago and it all matched BUT, the little BMW marks on both sides of the numbers were missing which indicates a re-stamp. I guess it's not the end of the world but I may not have bought it if I would have known up front. These bikes are fairly expensive to restore and a lot of value is lost with bad numbers. Just a heads up.
I borrowed the picture from ManxNorton