R25 spares

A friend of mine has a mate out in Greece who runs an R25. Apparently he's after a petrol cap and some or all of the ignition system (it does run, so I'm not sure exactly what the problem with that is).

Does anyone have any pointers for where to track down this sort of thing?

Bump!

Any ideas on possible sources for vintage spares? It doesn't have to be UK-based, and I speak a smattering of German so I would be happy to post on German websites as well.