thank you for the responses so far. That is interesting to hear about the Marlin. That is the one gun I have a vague recollection of shooting when I was a kid.
But all of the guns show wear from heavy use. I appreciate hearing what I already suspected: that at least the Winchesters aren't particularly collectible.
I just can't imagine having a classic car sit in the garage an not drive it from time to time. Likewise, I think it's waste just to let these guns sit in my safe.
I guess I was looking for someone to say "heck no. you can't hurt on old, well used gun by putting a few light dove loads through it."
I suppose what I will do is take it to a well-respected gunsmith and get his opinion on whether the guns are safe to shoot. If they can be shot, maybe I will invite dad out to the range to try them out. He may be 70, but he still shoots 3-gun IDPA.
Thanks again. If anyone has anything else to add, I'd love to hear opinions.