From the 1970-80s onwards, DAG, MEN, Hirtenberg, and FNM Portugal All supplied the BundesHeer with 7,62 Nato standard ammo, and the Packets were all similarly stamped with the relevant details, only the manufacturers’ Logo was different ( and Lot numbers); they were packed either in 1500 round German Patronenkasten (Timber), or 1000 rounds in 200 round Plastic “Battle packs”.
This was the German standard at the time. And being “German” all the Boxing, Labelling, headstamp layout etc, was the same standard. ( irrespective of manufacturer.)
As to the ammo being very similar in appearance, the Machinery used by nearly all the makers was Modern German or Belgian machinery–Fritz Werner, New LaChaussee, etc ( Even the Nigerian 7,62, made on F.Werner equipment, resembles the German Nato ammo.
Cases of all these makers are top quality, Berdan, Noncorrosive, and with the right tools, eminently reloadable. I have fired and reloaded thousands of them, back in the 1980s.