Only one way to find out mate, enter it and see how you get on, looks very good from what i can see, concours has changed all the classes this year more info here.

http://bbs.rsownersclub.co.uk/showthread.php?t=85195

and you could try comparing your car to some of the ones on this site that would be in your class

http://www.rscarshows.co.uk/