I know this isn't TT related but hopefully someone will be able to help.
I have got one of the original Spondon rolling chassis's from a Sparton 500 "4 cylinder" bike, (not the triple). Spondon Eng. have confirmed from the frame number that it was built for the factory "team" bikes.
I am desperate to get any photographs, pictures, drawings information etc. on the 'works' square fours. Preferably without fairings, for a possible rebuild. I will probably have to use a Suzuki motor, ironic really as they stole the design.
If anyone can help or put me in touch with someone that can please drop me an email.