They are date code stamped on the barrel on left side in front of receiver. A barrel location diagram and the date code table (month/year) is available on the Remington Society of America.
300-400 USD
Impossible to answer without the sn.
It's date code stamped with month and year on barrel, see related links for information on the Remington Society of America.
1916
February 1943
You will have to contact Remington.
Compare letters in front of receiver below and behind choke to these on this page. http://www.remingtonsociety.com/questions/BLACKPOWDERX.htm
August 1943
1911
value for remington light twelve sn 3g20225?
Is this a model 11 Remington? Please re-ask under the Remington classification
Browning.com has sn data under customer service.