On the bottom of the barrel where it meets the chamber.
1946
200-500 depending on condition
http://www.nrapublications.org/tar/Ithaca37.asp hope that helps
Historical Overview of the Ithaca Gun Co. says that in 1987 Ithaca Acquisitions, Inc. Moved the gun making operations to King Ferry, NY. and changed the model m-37 to model 87. In 1996 Ihtaca gun Co. LLC changed it back to model 37.
1947
The Ithaca Model 37 shotgun was first introduced in 1937, and it has been produced in various gauges, including 16 gauge. The specific year of manufacture for a particular Model 37 can often be determined by its serial number, as Ithaca Arms Company used a specific dating system. If you have the serial number, you can look it up or consult resources dedicated to Ithaca firearms to find the exact year of your shotgun.
easy Look on the barrel it should say if it a Model 37 , or Model 37 Featherweight, but the main Point is it should be on the barrel what Model it is
Watch Gunbroker.com - they often have barrels listed. Also you might try Ithaca Gun USA, a company that has picked up the rights to manufacture the Model 37.
The Ithaca model 37 has been manufactured pretty much unchanged since 1937, so you be the judge if it's a good gun. The name was changed to model 87 in 1987 but changed back to model 37 around the year 2000. I see no listing for "Featherweight" although there is a "Featherlight".
See Related link
What is the condition of the gun and the barrel length?
Ithaca Gun Co only used the seven-digit serial numbers in 1968 and 1969. Your Model 37 was manufactured in 1969.