Try e-gunparts.com
$70.00 to $125.00
Your Stevens model 15A was produced from 1936-1945.
The savage/Stevens model 94 was made from 1929-1945.
The Stevens model 944 was made from 1936-1942.
Hard to say without a much more detailed description of your shotguns overall condition.
Model 940e 16gauge
stevens bolt action 22 model 840
Your Stevens model 77F was produced from 1955-1971.
The value of a Stevens 820 B shotgun is actually dependent upon a number of factors. Some of those factors include the age and condition of the shotgun.
The Savage 820 model is an older gun that was made long before the current accessories. No one ever made any after-market accessories for this model, it is not noted the year of manufacture.
52 years old.