My take for whatever that's worth....
Given this was your Father's gun. I'd try to find a reputable "stock" guy to repair and possible recut the checkering and refinish the stock. The fact your father or someone in your family etched the chokes of the barrels on the flats is just added history on the gun. Like has been said, this is not a "collector" gun, and it's value comes in sentiment, not dollars.
Get the stock fixed, maybe have experienced gunsmith do thorough cleaning and analysis on it's shootability. Get some RST 12's and go shoot some birds with it once in a while. Rest of the time, hang it on the wall and cherish the memories it has been a part of.
But hey, that's just me...
