That is impossible to determine without knowing the manufacturer and model of the shotgun.
If it is a double, remove barrel and you will see it along with serial #.
nitro hunter shotgun single barrel with exposed hammer stamped belknap hdwre and mfg serial 5516
Can't be answered as asked
There should be a stamped model number on the left side of your barrel. The serial number will be on the reciever; however, the model number is on the barrel.
as your looking down the gun, the gauge should be stamped on the left barrel back by the stock.
Generally it is stamped on the side or top of the barrel near the receiver.
Made in 1934.
The model will be stamped on the barrel right after the Winchester name.
Blue Book of Gun Values will help.
Remington 11's are essentially Browning type shotguns with lesser values because of the name brand associated with the latter manufacturer. It is possible to find a Remington model 11 with an extra barrel with a different choke. The installed barrel and the extra barrel should have serial numbers.