How long is a Stevens 311a shotgun and where are the serial numbers located and what are they worth and what years did they make them and are parts hard to find for them?

Here's a partial answer.. I bought a one new for $59.95 from a factory ad in Popular Mechanics magazine,in 1969. They were considered to be one of the cheapest on the market at that time. Mine does not have a recognizable serial number either. I hunted rabbit for many years and eventually cut the barrel to 20 inches for a home defense weapon.