JohnfromUK,
I don't think this is the "peening"of the hook, Joe was talking about. This was only tightening, not putting it back "on face".He specifically said he wouldn't work on the "hook" to tighten.I'm sure what Joe was talking about is the often seen punchmarks on the hook(the front lug)in a misguided attempt to set it back.This poor method is very obvious,even to the untrained eye.What the English trained gunsmith did in the video is not obvious and I suspect a lot of us proudly showoff guns that have had the samething done, without knowing it.
Mike