Halo Air Assault Helmet Mk1 & Mk2

Hi Donny, I found a version I had that is the MK2, I've Converted yours as in the MK1
But they quit large due to the neck hole in MK 2 being 17- 18cms across to get a large adult head in. Yours the Mk1, I think its sized right but will need some bits at the bottom to dremmel out to accomidate the ears going in. let me know what you think or where it can be changed or improved on, Cheers Jace