At the GSSF match last September, the Armorers told me of an issue they were aware of with the older, Gen2 frames, where they were prone to develop cracks just behind the locking block. The good news, they told me, was that if I would take it by the factory in Smyrna, they would be happy to do some work to the frame that would prevent the cracking.
So, yesterday, I had some free time, and made my way to Highlands Drive in Smyrna. After signing in, I went to a waiting room, where I was met by an Armorer who knew just what I was talking about.
After about 30 minutes, he came back with my frame, which was cut thus, and the plastic rail relieved some ahead of the cut.
Like a dummy, I didn't think to take a "Before" picture, but here is a picture I found online for comparison:
Of course. in the process, the Armorer also replaced all the internal parts, so Frankenglock is all set for another 20 years or so, till I pass it down.