I've been concentrating on the Glemseck project for the past 8 weeks. The Virago's been collected. Got it back, new battery and 3 prods later it burst into life and settled down to a purr. It had been stood for 2 years without being started - but only done 13K miles with an obscene amount of money spent on Yamaha official outlet maintenance ! It really is a little jewel.
At least I can now take some proper measurements and get the POC idea going.
Latest thought is to sell everything bar the engine and ancillaries - that should return me about £400 - £500 more than I paid for it ! That will more than cover the cost of a bespoke frame - without taking compromises.