For what it is worth the rear (crescent tip) exterior chrome pieces are individually fitted to each car. If you planned on re-chroming them and use them on another E9 , do your fitment first (filing the rear perhaps) before sending them to be chromed. They are solid brass. For exterior pieces try to save the clip if they are not rusted out. I have not been able to find replacement yet for the clips. Do not worry about trying to remove the rubber from the front squeegee. Most,if not all chrome shop have chemicals harsh enough to desolve the dried out stuck rubber. As is hard to do by hand for no good reason....
Both top and bottom rubber are available from W&N and BMW . However squeegee velvety felt is not. so you have to either use your old one or go with something generic!