The C15G is the last C15 from 1966/67.
Engine and frame numbers were the same, prefixed C15G.
The engine the best C15 engine, much improved over the earlier models - ball and roller main bearings rather than ball and plain - better oil pump with crankshaft end feed for big end- stronger Victor stub tooth pattern gears with needle rollers on the layshaft ends.
Made less than 2400.