I believe when you get the new piston, the clearance will be much less than .010. More likely it’ll be around .0025-.0028. Seized pistons generally collapse some. Once you have the aluminum off the nikasil using acid, (do NOT over do this! Remember, nikasil is porous and the acid will go through it and deteriorate the aluminum underneath if you leave it on it very long) the cylinder doesn’t need any size taken out of it. It just needs a standard hone ran thru it to make sure there isn’t any high points. Don’t try to take any scratches or scoring out. It’ll run just fine with them there. My fastest Pavesi cylinder looks terrible, but runs very well.