[PNJSNAK]

I agree with Roscoe. Do not try to use the existing holes. Too much chance of ctracking the glass if the screw length is not just right. I did not tap the frame, because it is chrome platted brass after all, I thought too much chance of stripping the threads. I just drilled thru and used stainless screws, washers and nylok nuts. Looks great and no worries.
Jim