Bob, I dont see why not if you built & owned them, the problem as you state is how much 'creative licence' you use in building that replica, after all I assume you probably 'know' more now than you did at the time you built those cars & naturally would with the benefit of hindsight do some stuff different, I wouldnt think that would be a major problem, take for example if someone else fronted up with one of your old cars & asked you to help..would you leave it exactly as it was or make minor developements that might help it. In a perfect world that sort of thing would be self policing, problem is this avenue of motorsport is supposed to be 'country Gents' type racing, more about a brisk demonstration of the car rather than out n out racing.. many of the drivers still think they are 20 odd years old & bulletproof & once out the pit gate it is a free for all, what really worries me at times is how many look like they are about to have a stroke or heart attack at race end