Hi, I'm trying to fit a solo racing seat(bum stop) type. on my 78 CB550K. I'll hack up a generic fiberglass one if I have to but I'm really interested in fabing up a bolt on seat GB500 solo? maybe...

/any ideas? or leads in finding a seat to fit this bike? I've gone to a few glass sites / british sites but am finding it tougher than I thought Help!!! thanks, Kfitz