As an outside observer, I would make everybody produce their original purchase receipt dated pre-1990

!
Failing that. Box standard kits (no upgrades) with a release date pre 1990 and perhaps a seperate class pre 1985 (at a guess) for the likes of the Hornet and Hotshot etc. Could race togeather but have two classifications.
I would be interested in a race or too with my old procat. I'm a bit worried that you guys consider a guy who gets into reginal B finals as a middle ability driver! Maybe u could also have a handicap system for vintage racers who haven't actually raced since 1990 either