I thought the Manx was friendly and fun!
I think cregs problem is how he has interpreted the rather vague rules from the 2010 regs as opposed to how Trident Racing(the bikes builder) have.
The rules state that wheels must be of a size 'available at 31st December 1985'.
There is no mention of width or whether they were actually used.
I feel sure if you had ordered a 6 inch rim from Dymag in time for Christmas in 1985 you would have got one.
Eddie Lawsons works Yamaha probably had a 6" rim 'available' if he had wanted one.
There was no mention of tyre width in 2010 unlike 2011 where the maximum tyre width is stated as 180. Again no mention of rim size.
There are probably loads of other 'eligibility' issues to deal with like longer H model swinging arms, Slingshot wheels and seats, Yoshimura fairings etc on GSXR 750s. Perhaps they were 'available' as well!!