New Scattergun : Question

Vitals:

  • Stevens (Savage Arms) Model 9400
  • 12 Gauge
  • 3" Chamber
  • Exposed hammer
  • Single Shot (break-open, strange side-lever)
  • Still looking for a serial number... there isn't one visible on the receiver anywhere.

    This isn't an old, rare or high quality gun, but I can't seem to find a lot of information about it on the interwebs (like when it was made, or how many they produced.) Does anyone know more about this gun? All I know is that my granddad bought it (possibly from Sears) at the same time he got my dad a Remington 878 Automaster. The gun is in nearly perfect condition (just a wee bit of rust near the muzzle, and a couple of very minor scratches on the furniture.) It looks like it was shot once or twice max, then put away in the attic.


    (Cross-posted from West, By God)

    Additional: I really need to find out if there is a possibility this gun was manufactured before 1959. Any thoughts? I know the Remington 878 Automaster was manufactured from 1959-1962.