Rog G yes I have same chassis and the matchless MX water cooled side valve engine wheels need tyres off and powder coat dont know if to go for silver or black wheels, tyres are knacked so thinking brockleys?
Can recommend GKL powder coating at Snetterton for such on 01953 888215.
Mine after blasting to remove original black then coated in metallic silver and laquer.

Still perfect after 18 months for under £100 the pair.