I live about 15 miles from the FFR factory in Wareham, and I've been to several of their open houses. What I've learned is
that they used an existing set of molds for their bodies--some say Contemporary. The other view came from my own observations of Butler cars---(I'm a brand new owner of a used Butler myself)---the Butlers have "built up" widened but not raised rear fenders. The Butlers are able to mount hugely-wide rims and tires in the resulting space, provided that the Jag rear is moved an inch or so aft to avoid the seats. The FFR appears to have the opposite modifications. The rear wheel-well stays within Cobra specs but has a higher build-up or profile. There seems to be a narrow "crown" to the rear fender.
That's the only difference I've seen. I DO know a lot of owners of various makes have compained that 295s and 305s (on 15" rims) "rub". Most people fix this by going to 17" rims and lower-profile tires. They then can get 335s on SPFs, etc. with ease.
Hope this helps.
