I don't believe you can determine year of manufacture if it's that old. Stevens (Savage) did begin using a date code in the late 1940's, but they were no longer making guns under the Eastern Arms name by that time.

Someone with a 5100 will confirm, but I can't recall whether those guns had the same action profile as the 311, which fits your gun. So does the 530, but those guns had checkered stocks, which yours does not.