And (seeing as I'm on a role), as Sports Sedan races were historically all-comer races, ie, anything with a roof, why wouldn't Historic Sports Sedan rules be based on the same free spirit regulations? Why not alloy any touring cars that raced within the years you have defined (except early V8 Supercars)? Group C Touring cars were regular starters in Aussie SS races, and several raced here in NZ SS races during the '70s, as our season has always been over the summer months.
More and more 'historic' Sports Sedans, OSCA (Open Saloon Car Ass), All-comer, and Shell Sport ('70s 2 litre SS) cars are appearing in historic racing events here in NZ. There is always a place found for them.
Check out this amazing piece of wild Kiwi racing history:
http://www.trademe.co.nz/Trade-Me-Mo...n-96186257.htm