Oops, I don't remember noticing this. If I did, I probably chalked it up to the reputed nature of these beasts for their huge tolerances among all the parts. The gun had worked OK during the several mags of ammo I put through it while I was its foster parent. I'd addressed a couple of issues involving metal displaced from use, and this issue would also be good to fix, if possible, to continue the pistol's "improvement."
(For everyone else reading this thread, I'll confess to selling this pistol to Rich, who was finally able to pick it up this week. I'd acquired it from another forum member several years ago and decided to pass it on after Rich tracked me down as the current owner, based on my posts in the WTS when it was sold to me back then.)
Now that we're into this issue, I'd go with the approach of building up the front surface of the lug. But first It would be good to check to see that this "adjustment" would affect anything else, such as the side plate's interface with the end of the sear bar/plunger.