red jacket converts saigas. their prices compared to what you're getting is laughable. you're buying basically will's smile. arsenal often uses bulgarian receivers. not bad. worth the money.
lancaster used to use nodak spud receiver. nodak spud from a north dakotan potato farmer who was involved in the design. hence NOrth dakotan SPUD farmer. early lancasters are good but in all honesty the later ones have canted sights. poorly installed rear trunnions that elongate the rear rivets which cause the dust cover to eventually come loose / pop up. there is a reason that lancaster stopped selling directly to the public.
my question to you is would you buy an AR made by a russian company or russian derivative? commy gun. commy manufacture. good luck.