Hi Frank! The Imperial Frontier All American series was introduced in 1985. There were three lockback knives in the series, AA-31 (3 1/2"), AA-41 (4") and AA-51 (5"). They have one-piece boster/linings, nickle silver shelds, and 440 stainless .072 blades. They are American made, but not by Imperial (which factory in Rhode Island was being closed and mved to Ellenville), or even by Schrade. I have the Camillus "S" cards (dated January, 1984) which show that they were made in that factory for Imperial Schrade, assembled from parts provided by ISC.
Value? Imperial knives as a whole aren't very much in demand, but the All American series was only made for a short while and anyone who has two examples of the knives but not the third might be willing to pay more for the missing example.