I review the muzzle brake in Entre'prise FAL Receiver Review . The magazine floorplate and follower are perfect duplications of the original. The follower is indistinguishable from the original. The floorplate can possibly be differentiated by the angle of the perforations at the rear. These appear more triangular than a Steyr, but there are a dozen variations from different countries, and there may be one that matches the EAI perfectly.
Parts are excellent and perform as advertised.
I dropped the hammer into an otherwise original StG-58 lower. It functioned fine. The marking is clean and deep, apparently a laser engraving. It appears to be a casting from the porosity on the left side, however also has marks indicating it was machined. Perhaps a combination of the two.