This is a frame made in about 1980 by Mick Whitlock to suit TY175 running gear. It was bought from Sammy Miller in 1988 by a friend of mine with the intention of his riding it, but instead he bought a TLR250 and didn't persevere with building up the Whitlock frame TY175. The frame kit, gold rims and his disassembled TY175JC were stored until earlier this year when he asked me did I want them.
The frame was stored in a hot and humid place since 1988 so needed replating. I picked it up from being replated last week.
Mick Whitlock made two different frames for the TY175 running gear. One is about the same length as the standard TY175 frame, and this one, which is about 50mm shorter in wheelbase. The ones that Mick Whitlock sold had a uniquely shape fibreglass tank/seat unit and were called Yamaha Whitehawk. This one was sold as a Sammy Miller High Boy TY175 frame kit and came with a tank/seat that looks very much like the tank/seat unit made for the Mini-Majesty 175.
http://www.bikepics.com/pictures/2477755/