Have you pulled the Western style muffler off and measure thru the exhaust port with a popscle stick for Bore size. 6cube should be 57.1 mm and it is possible you may have a 5 cube cyl on that saw also which would measure 52.39mm.
The cyl looks like a chrome Mahale cyl ,it has the Prestolite ign module mount bosses on cyl. which would be correct for a P60 and
lt has the westcoast full wrap and west oast muffleron saw but those parts could have been swapped over.
Lf you could pull the Reed block out of saw and look to see if it has the metal reed or fibre reed , this info would narrow things down because all Western saws had fibre reeds.
The Piston rings are probably the thin ones which would be standard for the P60 and P61 .
The P60 would have the decompression valve in the top cyl head also.
The Btm frame colour in pic looks like it is Black , if so it has been swapped out of another Saw.
All Western Model Saws were Black Frames, Top & Btm