Help with 03A3 bayo lug

I bought a sporterized Remington 03A3 (3,943,XXX with original 8-43 barrel) a couple years back and have it back to original set up, minus the bayonet lug. I picked up a nice clean parkerized "R" stamped lug from Sarco and I think it's a repro. It strips the threads off the screws every time I try to attach it to the tip of the stock. I have purchased screws from various places so I'm thinking it's the lug. Is there a way to tell a fake? Or where to get an original? All help will greatly appreciated.

I think Bill Ricca is VG, or you might call The Dealers Warehouse. Springfield Sporters is very good. If you got it from Scrapco you can expect it to be from China.