Grade 3s were usually marked in two lines 'Hunter Arms Co Fulton New York on the rib extension near the breech. I would be suspicious of an unmarked barrel on a Grade 3 although it might be OK as a shooter with replaced barrels if priced accordingly. However, in our world of vintage shotguns we are always warned to not say 'never' so there is a chance the barrels are original but that's a 'long shot'. Hope this helps.