I converted my C100 to 125 power and used the complete wiring loom from a 12v Cub. It's true that you will need to trim the frame slightly to get the engine in, but it's such a small amount that it's not noticeable. HOWEVER: C100's have become quite precious now and I agree with the previous comments about using a 12volter instead. How about using a 12volt Cub,but fit a metal rear mudguard and a CM91 front end to give the classic look? If you got a "Cherished" numberplate too, it would cause some head scratching from the Originality Police.