I would characterize AGL's efforts to be on the pelagic end of restoration. Restoring suggests replacing that which was lost or damaged. Saving one pin, and calling a shotgun restored is a stretch.
Remanufacturing, using all modern techniques to modify an old shotgun action is the correct terminology. But it's not a restoration. The entire purpose is to end up with a modern firearm. Not to turn back the clock.

It's that "prior condition" definition that is the bugger.

Out there doing it best I can.