Humphrey here, he had 1 done, so I traded my parts kit lower to him and cash..
Lowers used were all from kits, and they have the "old" style parts in them, the wire to the disconect kept popping off, trigger would not rest, so I ordered late model parts from Vector to make similar as my IMI "B" group..
Watch when you work with yours, that the selector does not detent positively, as the metal piece he had stamped extends over the notch in the selector bar, so the selector does not lock well. Repair would be to remove some material from the metal nose so it not ride over the notch on the selector bar.
Other than that little quirk, mine been fine.