I had one of these in semi-auto and it was machined from bar stock.
It was soft, and the holes egged, which is why this one has the inserts. It should be fine for shooting now.
Back in the day maybe 10 years ago, Olyarms (SGW/Palmetto Armory) would replace these with new receivers, same serial number, but ATF scotched that.
My semi-auto receiver I sent back for refinishing and they sent me back a new forged lower with the same serial number. For free.