Another 273 commando build .. This one will be a "BEAST"

If the cyl are rusty get the rust off before removing pistons, I put the cyl down and use oil soaked 220 then 320 to clean the cyls then whip them out with WD40 on a rag once clean I use a wooden dowel rod to tap out the pistons
cyl walls are all very clean , don't see any rust at all.