Re: Remington simiauto shotgun
I am assuming the gun has a plain barrel (no vent rib).
A field-grade 16ga Model 11-48 in the condition you describe would sell for around $250.00, possibly a little more with the right buyer.
Your gun appears to have been manufactured in 1950. The Model 11-48 is a recoil-operated semiauto which means the barrel recoils into the receiver with each shot. The design originated with John Browning, and Remington initially produced that basic concept as the Model 11. Your model, the 11-48 is a streamlined, redesigned version of the older Model 11 that represents Remington's first shotgun introduced after World War II (the '48' designates the year of the design although it was not introduced until 1949). It remained in production until 1968 when the sheer dominance of the Model 1100 finally killed it off.
The autonomic nervous system provides for involuntary muscle function - the work of breathing, digestion, and so forth. On some folks, that's a pure waste of ingenuity.