Bellmore Gun Co was a store-brand manufactured by Crescent. I don't know what you mean by the "code".
Made by Crescent Fire Arms Co, 1893-1932. Worth $150-$250 depending on condition.
try gunstock inc. they have them
try gunstocks inc
In reproduction catalogs from Sears @ turn of the century
Any of the current stock makers should be able to help you.
AFAIK, there is no published sn data on Crescent Arms.