Most #4 front sight mounts I've seen are drilled in the front next to the bbl for the sight protector screw and have a diagonal cut extending from the front of the dovetail down and toward the back of the sight. But recently I saw a #4 which had a protector hole drilled, but without the diagonal cut, so that it is a solid block like is found on #1's. This #4 sight measures the same as all other #4 sights, but is lacking the diagonal cut. I think it was a BSA late WWII vintage. Just curious about why this discrepancy with what I thought was standard? (As if anything is standard with war time guns.) Thanks...