I know I'm late to the party, but man that helmet is incredible. I've been trying to kitbash a hybrid 3/Reach helmet exactly like yours for almost a year out of Reach models and you go and do it in your opening shot! It's based on the version in the CEA terminal cutscenes, isn't it?
I don't suppose you'd be willing to share the STL file, or maybe a pepakura for it? I'm in the process of planning a Package/Infinite/Reach hybrid suit and that helmet is the missing piece of the puzzle.
Hey there! Don't take this the wrong way, but I want the helmet to be my own signature thing and I really don't have any plans to distribute it. As DefineLuck pointed out, I had the file on my Etsy briefly, but that was literally just to sell it to a good friend. A rather clunky way of doing it, but eh. Maybe down the road I will release it, but not for a bit. At least not until HOD is all over with.