Try e-gunparts.com
50-200 US Dollars
I would start my search at Numrich Gun Parts Corp. They may be found on the web as gunpartscorp.com. Your JC Higgins 583.3 is likely a High Standard, possibly a model 514. Numrich has parts.
Best left to a gunsmith
looking for stock model sb 20 gauge
Most of these were made for Sears by the High Standard company, and was sold by them as the Flite King. Not a lot of collector interest, but a sound, durable hunting grade pump shotgun. Depending on condition, value is $100- $175.
I have parts for that model. sales@countrygunsmith.net
Nobel model 20 is the same gun for parts.
We have them. gunshop@nctv.com
I have quite a few. sales@countrygunsmith.net
A FEW parts are available from gunpartscorp website.
try this-------http://www.e-gunparts.com/--I know they have parts--Vail