When I ran a bmw I found Bemw in Derbyshire very competative on prices and again they build parts up with weld and reclaim etc, best known for their Chineese bmw /ww2 clone inports. I had 2 reconditioned gearboxes off them and a recon bottom end and everything functioned very well and was about half the motorworks or moto bins prices, sadly that was still more than I could run a cb500/4 for and the Honda beat the Bmws on charachter and fuel economy so the Bmw's found themselfs retired though they are still sat in the shed, the 1000cc twin plugged boxer with leading link forks and sidecar was indeed an awesome toy and could easily do massive distances in one go without wearing the rider out. I have a decent spare wheel that is slightly wrong splines for my R80 or R90 bevels somewhere in the shed, a scrapyard find that didn't work out - looks identical to my R80 wheels but slightly tighter splines - might be off one of the other models, but wont fit any of the 80, 90 or 100 bevels. I can dig it out if of interest.