is this a stock piston?

[crashedout1]

Going through the hot air engine was wondering if this thing was redone

 

[pdzz]

Looks like the pistons in the one I just pulled apart. Never opened up as far as I know. Was also standard bore.

 

[crashedout1]

Probably can't use them anyway got some rust in one of the cylinder bore measures 3.8 ill try to hone it out

 

[jiho2]

Look at it from the bottom.