[Gabor]

Hi!
I've opened up my recently bought 3 1/2 HP, because the small end bush was seized, and found out, that it has a 1922 3 1/2 HP longstroke bottom end with correct crankshaft, and a 1920 3 1/2 HP cylinder with a "foreign" cast iron piston (possibly early Triumph). This adds up to a 4 1/2 HP.
What I've found out so far is, that the 3 1/2 HP and the 4 1/2 HP shared the same con rod. So the compression height of the 4 1/2 HP piston has to be 7.5 mm shorter, and the skirt too. Can somebody help me out with further details (rings count, size, etc), maybe some pictures?

Gabor