That is true, but also a slippery slope that, in the past, has led to justification of direct recasting. With regard to the GMH and any helmet with lineage, it is hard to say what they were "meant" for. Likely, most of those castings were simply made for friends of friends 30+ years ago because it was cool and laying around in someone's shop. They never thought beyond that. You still see this happening today in the prop and model shops. Test castings. Castings for friends. Castings made specifically to backdoor out into the screenused market... there is never a thought about someone getting one and recasting it and if you asked most of those people, they wouldn't care or think anything of it.
Recasting has ALWAYS been a very grey area with NO moral high ground, only differences in opinion on what is ok. With the digital age upon us, that needle is moving again.