Two true '72 Combat factory standard in every component engines, no base plate, both pairs of, 10:1 CR, round oil hole and comma oil hole pistons, all stood .050" proud of cylinder at TDC, give or take a 0.000X", mostly from piston top cleanings,
Nice accuracy of a Norton product, in this particular aspect of 750 engines.
Alas, all un-indexed 750 cylinders' top decks, are milled with a slope for total of 0.003" difference. Low towards the rear, IIRC but check for sure on all of yours.