Just chucking an idea around Will - I'm not saying it HAS to be 30. It's desirable to have star riders on exotic machines to attract a bigger crowd but then that will take the replica winning time out of reach for many that might otherwise deserve it. There's a guy who posts on here sometimes who rode in the Classic Senior last year, finished well up in a good time but didn't get a rep because Farkie had been so quick on the Paton.
Maybe bring in Silver & Bronze reps. Silver to the first 25% of finishers, Bronze for the next 25%. I certainly wouldn't want to devalue a replica but I do believe there's a fairer way of doing it.
I also think it's safer (and I apply this to the TT aswell) as I wonder if sometimes riders chasing a replica time ride a little beyond themselves to try and achieve it?