upol clearcoat is none isocyanates its a one pack .The only reason i mentioned it ,was that applying it over your cellose ,it will stop it losing its color after a while,as it has no UV protection against the sun.We never had that option in the seventies.
For info "isocyanates" is the stuff you call the nasty one
You can try a couple of ebay shop in the UK Jawel-Paints and Nu-agane.
I have not used either of them, but planning to they do deliver, I rang both of them and were very helpfull.
You will also need gear for preparation and stuff, I have done a quote for me a couple a weeks ago and it turns out £600 including paint which is not too bad.