1935 Triumph 500cc...
Triumph 1935 500 cc OHV Project, probably Model 5/2
Engine number: 2.S5.1678 Frame number: F1240 or FL240 (hard to see)
Year: 1935 Cylinder capacity: 500 cc
Engine seems to be partly overhauled, but the top end is not put together.
Gearbox turns and feels good, the clutch can not be guaranteed if it is complete, as it is in parts.
Regarding completeness, please see photos available or...