You feel confident that 1 example of a #1 fitting on a #1/2 is enough to be sure they are all close enough?

If there is a 1/16" difference in firing pin centers between a #1 and #1/2 then even if the barrels fit the firing pins will not be striking the center of the primers. Will it work? Probably. Is it a righteous in the eyes of Charles Parker? No.