Look at the serial number. The 392 is a Crosman built rifle so it has a Crosman serial number. The first character is the month code 1 through 9 for January through September, O, N, or D for October, November or December.Second two characters will be the year.For example a gun with a serial that starts with 978 would have been built in September of '78.
This is the nb#207700214 . its all brass and its a ball to shoot.