Stevens 620 Buttstock ?s

I have a Stevens 620 Riot Gun with with military markings. It's a mismatch, 3 different numbers, and the barrel was threaded for a Weaver choke. I'm trying to find a proper buttstock for it. In looking at Numrich's 620 schematics and whats offered on Ebay for 620 stocks, everything I see uses tang mounts, not a through bolt. Does anyone have a source for the proper stock for this? Did the riot guns have sling swivels? I know it's a riot since there are no notches in the barrel for the heat shield. I am tempted to buy the repro shield offered on Ebay for $175, but I think I'll just use it as a shooter. Does anyone know if the Cutts Compensator uses the same threads as the Weaver?

Gunluvver, the old Stevens Model 620 stock shows up occasionally on eBay in used, most of the time cut for the trench gun lower swivel I remember seeing an SARCO ad awhile back offering the 520-30 and 620 stocks for sale. Personally when I bought one with the usual bad/broken at the wrist stock, I bought one from Boyd's and fitted it up. Looked great and I was pleased. Finished it up with lots of coats of BLO.

Just a thought.