Update:-
I met the lad last night at Wetherby services and he turned up with the bike in the back of a van, very strange!
Bike had been painted, had racing tyres on. Looked nice but very suspicious vin plate. We swapped bikes for a test ride and he asked if I wouldn't mind him winding mine on a bit. This lad was a total nut and at one point I was doin 150mph (off road obviously officer) just to keep up with my own bike!!
Didn't buy and to be honest wasn't that blown away with the performance so back to plan 'B'