How to register an old firearm.

[u/TheRealRyan24]

I have a friend whose dad has had possession of his grandparents old 22 and 12 ga for decades but the parent has not had a pal and they believe the guns are currently unregistered. Is there a proper way for my friend to takeover possession of these guns. (Sidenote the guns have sat way away in storage for literal decades and have not been fired in that time)

[u/outline8668]

What year is this???