So after doing a bit of searching on the web I found a post from a member on this site from a while back saying that he had bought some from a company called RS Motorbike Paint. You put in your make, model, year and it came up with (38582, Metallic Mystic Silver), 400ml aerosol for £19. Down side is they charge £10 postage so I might give some steel wheel stuff a go and see what it looks like.