Helmet size

Hi all,
I have decided to try and make my first scratch build helmet.
I’m using the WOF templates I downloaded and am following the great tutorial by digifett.
I thought as I’ve never done anything like this before I’d make a cardboard prototype to familiarize myself with the templates.
I thought this would be good for two main reasons, the first is that if I make any silly mistakes with the templates it will be easier/cheaper to rectify rather than if I’d used polystyrene or some such.
The second and main reason was that I wanted to check that the size of the helmet would be ok for me.
I’ve completed my prototype, it fits fine and the proportions seem ok to me but I thought I’d get the experts opinion on it so below are some pictures:-

I’d appreciate any comments or opinions.

Anyone have an opinion on the sizing?
I'm reluctant to start on the proper build until I have some expert advise.

Looks good to me proportion-wise.
As far as the actual size goes, I have an FPH helmet and it measures 10 1/4" (258mm) from side to side at the "ear flats."

Looks good, but I'd probably make it just a tad bigger. I feel as if it's a little short for your build