Its a bit pointless to do the grinding he done at the end, its much stronger weld if you leave the beld as it is... That can snap 1st try when tightening the bolt back on... It looks a good repair though...
I don’t think he took much material off, plus it is smoothed and blended which removes any stress risers.
I’d wager he primarily wants it to look original, and he did make an impressive job, not that it looks like some rare vintage component. Odd how it snapped to start with, I doubt simple over tightening did that.