Try egunparts.com
Try Numrich Arms, also known as Gun Parts Corp. They have a website.
Follow the link below to the parts diagram from the Numrich Arms website.
brownells.com
Marlin Customer Service, or the website for gunpartscorp.
Sadly, your rifle has been out of production for a LONG time. You can check with Marlin thru their website, or have a gunsmith check his sources for used parts.
Your rifle was made for Sears by Marlin- it is their model 81- a popular rifle. Parts may be available on their website from gunpartscorp, or any good gunsmith.
Try Numrich Arms, also known as Gun Parts Corp (GPC), they have a website but you're better off calling them.
Just guessing, but sounds like a Mossberg. Depending on parts, the best source is usually Havilin Sales. You can find a listing of parts on their website.
Numrich gun parts
Your rifle was made for Montgomery Ward stores by Mossberg, and is a Mossberg 346K. You can check with a gunsmith, or check the website for gunpartscorp (look under Mossberg). Havlinsales also stocks many Mossberg parts.
Unfortunately your Model 10 Mossberg (one word) rifle was only made from 1934-1936, with the end result that parts will be VERY hard to find. Gunpartscorp has only a few parts for these on their website. havlinsales has many Mossberg .22 parts (and run the Mossberg Collector's Society) Finally, a good gunsmith can make many of the small parts that you rifle may need- but finding parts WILL be difficult. Good luck-
Made for Coast to Coast Stores by Mossberg, it is a Model 479. gunpartscorp lists SOME used parts for your rifle on their website- check under Mossberg 479. Your rifle has been out of production for several years, so used parts may be your best shot (pun intended)