Honestly most of it has already been posted on this board in other threads, it's all stuff you can get by some careful googling. I will include below the tech drawings of the lower receivers I forwarded on though as I don't think anyone has posted nice clear ones here yet;
I'm pretty sure I know what happened with G&G and their "C7A1"... Someone who was tasked with doing the research on this rifle did a cursory google search and came up with this graphic;
Which is used by world.guns.ru and a bunch of other sites, labelling them "C7A1 and C7A2 rifles".... I don't know who came up with that image but looking at this graphic, and then the G&G C7A1 it's pretty obvious what happened.