Hello and welcome Christopher. You might try our standard ‘go to’ places. Sooner state pawn, Village Tactical, Oklahoma machine gun inside of Wilshire gun. No promises though. You could run an ad in the ‘want to buy’ section of classifieds but most guys are holding parts pretty close.
I just ordered one from Palmetto Armory not a cheap one but they had it in stock and I got it within a week or so after ordering. Just a thought if you can’t find one locally