Curl,
I am not certain that the age of firearm has anything to do with custom duties. A single gun imported for personal use may have some exemption.
I have imported several guns from various countries over the years with no problems once the proper federal import documents were obtained.
However last year I purchased a gun in Canada that qualified as an antique (age + being a cartridge gun "no readily available ammo being manufactured") but could not find a shipper because there were no documents with the gun. I wanted to insure the gun and list the contents of the package and no shipper would accept the gun without US federal paperwork. I ultimatly hired an advocate to go get the gun for me take it across the border (armed with a ream of paperwork indicating the guns age and all the Federal laws applicable to the importation and definition of an antique) to take the gun through customs, cross the border then ship it from the from the US side. A lot more time and expense than I anticipated.
Last edited by PM; 04/14/09 11:21 PM.