An even harder asspect is the factory LBHO release button thru the center truniun block.
Gas block has been available, Op rod no problem, tappet no problem, rear sight block with real removable AK furniture, very few I've seen do it.
Hinged 030 style top cover with rail even fewer I've seen. I have done a lot of research and have found very few gunsmiths / machinist that have even attemped to custom fabricate some of these parts. I do agree the parts can be reverse enginnered but at what cost?