The rear lug appears to be ok and fit right.
My guess with all of this is that this entire batch of stupid is intentional on the part of the idiots at Baer.
I don't want to use smaller pins, mod the pins, or anything else. The upper is the problem, the upper needs to be fixed or be trashed. I'll make attempts to reduce the size of the front lug first and go from there. I'm going to measure it and measure a bunch of other lugs to get an idea of how much is involved. Once that's resolved I'll look to the pin holes.

