Dom, why not run a 583 with a big bore kit in the 620 class ? Surely that would keep everyone happy ?
On a personal level I wasn't allowed in the 583 class and I have raced less than you and don't hold a National Licence. Had I have been allowed to race a 583 I could have saved myself over £3k in bike costs.
[Edited on 13-11-2005 by couchcommando]