4
According to OldGuns.net, the year of manufacture for Winchester Model 1912 serial number 466271 is 1927. Not sure if this is your gun, or what the value is.
http://oldguns.net/sn_php/winmods.htm gives the date of manufacture as 1918. In good condition, I'd say around $500. In fair, a hundred or so less. Not worth near as much as owning an old gun, so it's probably not worth selling, as the value hasn't increased as much as other guns.
your winchester model 12 shotgun was produced by winchester in 1925.As to the value these fine winchester pump shotguns are selling for between 250-500 dollars depending on the amount of original finish remaining on the guns metal and wood.If your shotgun has a vent rib barrel you can add 40-50% to the above listed price quote.