Wally, First let me say thanks, they were a joy to find and haggle over. I was also shocked to see the price my Son realized on the 1949. He received a couple of quick offers in the $500 range when he first listed it. I told him that was a very good sign and to never sell early, better to wait and let the auction complete.

Your Imperial is fairly uncommon. I have seen a couple with your marking, there is also 1968 version with the "8" clearly stamped over a "7". In my opinion, the rarest Imperials to find are 1977-1979, very few were made.