Thanks Jamabikes, it would be nice to think it's inspired someone too.
Really enjoyed doing the little modifications, need to crack-on with making a frame of my own up. Thanks to the Retrobike community for the help with bits (rear rim, forks, brakes, rear hub, shifters, seat post clamp were all sourced off here) and thanks to Gil_m for the decals and B3 for the disc tab.
It's still not quite finished, I'd like to fit a slightly longer front brake hose (if anyone has a 5mm hope hose - or just the 5mm fittings drop me a line) and I'm trying to decide if a 185mm wavy rotor would be a good idea or not (I think RC31's are 165mm max disc size?). Also, does anyone have a source for the later RC31 decals? I guess Gil_m should be the first person to ask?
Thanks for looking