This is still a bit of work in progress, I plan to update the model to fix a few inaccuracies soon.
The helmet is currently scaled about 23 in diameter head, though you may need to adjust it as needed.
Check out this video where I show how I finished the helmet and cosplay: https://youtu.be/zWFb8qF_otg?si=e32Qatcj615izuAG