Sounds like you have a Stevens No 35 "Off Hand" Shotgun. These are sometimes called an "Automobile Shotgun". They were made from 1923 until 1935. There was also a No 35 Autoshot ( 1929-34). Unless the gun is registered with the BATFE and you hold a special Federal License for the gun, it can be seized and you are subject to 20 years in Federal prison. It cannot be sold, transfered, or owned unless it was regestered back in the 1930s and you have all the paperwork from then until now.
The Feds are very serious about these guns. If you have one, I would cut it up and throw it away in a very deep lake.