Is it an old motor or one of the new ones? Ditto frame? Is it a Manx frame or a 'bed?
JUst wondering because if you have the cash you could build it from new parts, or a new engine in a Dommi frame etc and have a nice bike for much less than an original.
A quick google turns up replica Manx frames at £1200 to £1500 and replica G50 frames at £2500 to £3000.
There we go Replica G50 lump in Replica Manx frame - £1000 to £1500 less than replica G50.
Sorted....
R