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.
the 'PA' after model number designates "Pump Assist" and its a Mod done by 3rd party for Benjamin/Crosman a few years ago where a 3rd set of levers is added to the pump handle (compare how it looks to standard models 2 lever design) this has been talked about and youtube videos on it on the web. it reduces the force needed to pump gun by half with a cantilever system while not lowering pressure or adding strokes needed to do the same job. it should be adopted by Benjamin on all multi pump guns so kids and elderly can better use them. it would increase sales 5x at least for those model guns and not add much cost at all to manufacturing nor change how gun looks or shoots. its only noticable while pumping. I would very much like to get one of these guns in not just 177 and 22 calibers but also 2ocal and BB for me and grand-kids to enjoy. it stays under 14lbs of force through 8 pumps where standard models increase to 30lbs by 8 pumps. yet can handle increased pressure adjustment to boost velocity to over 700fps at 8 pumps which is max factory recommendations. there is also a 5 part review on this on Pyramidair site archives. I think its the best mod ever on a 70 year old design and makes such guns much more desirable. the Sheridan streak lines could also use it. and Crosman multi pumps if still made. also Crosman should consider re-introducing 20cal rifles and pistols to the multi pump and CO2 lines. at least customs.
I must have very late production 397P. Soldered valve but made in NY.