Depends on where you are located. Somewhere between 4-8000.00 US dollars. Hard to find guns.
56 years
If it's in very good condition, maybe about $125 or so. I have one and it is very accurate.
Depending on condition, 75-150 USD.
Unless you provide the name of the maker, no one can help you. Even then, the records may not exist.
Twenty dollars...
$20
Anywhere from $20 to $2000. Depends on the revolver, its make, model, and condition. An RG brand revolver might be worth $20, a high end Colt or S&W target revolver from the custom shop will be worth a lot more. If you can post here again with some information on your revolver, we can try to give you a better answer. PS- in the 1896 Sears catalog, their cheapest firearm was their 69 cent .22 Short revolver.
1973
Serial numbers were not required at that time.
twenty dollars
$20, American.
1967