westernfield pump 20 gauge

Question
I just picked up a 20 gauge for my son.  It looks like a Mossberg 500 in build.  The markings show it as a Westernfield.  The previous owner made it into a "riot" gun and cut the barrel.  I was wondering what kind of barrel (and other parts) can I buy for it(would Mossberg or any other brand swap out w/ it)?

Answer
Nurmich cross reference shows most of these guns made by Mossberg with a few made by other companies such as Marlin, etc.

My guess would be that once you know the appropriate model, Mossberg parts (assuming that's what it is) should fit it, although sometimes proprietary changes are made on contract guns.

Your best bet would be to take it with you to a gun shop that is well stocked and look at the parts to see what fits.  If you buy parts via the mail through a company like Brownells you can return them if they don't fit, as long as they've not been modified.