first you find the most attractive shotgun you can find then you want to go out with it... much like the ladies.....
Try Browning.com
Knickerbocker was a house brand name for Crescent Arms shotguns distributed by HD Folsom. All you can know for sure is that it was made before 1915.
What is the Model, Serial Number and date of the Crescent Firearms shotgun which you want a value on?
Maker's use different dating codes.
Go to Browning's site, click on Support then date your firearm.
If data has been published, you might be able to find out the date made and specific model.
Stevens 940 shotguns have a letter after model number is a way to date this gun?
That patent date is found on shotguns manufactured by J. Stevens Arms & Tool Co.
Go to the Winchester Official Website enter serial # and it should be able to look up the specific gun, and hopefuly the manufacture date
I do not have a current listing for that gunmaker. The proofmarks under the barrel will help date the piece.
Monsters do not exist, therefore, they are not immune to shotguns, nor are they immune to shotguns.
To my knowledge Beretta does not date stanp their firearms. If it's important you might try their website or write to their U.S. importer Beretta U.S.A. Corp. located in Accokeek, MD.