I had to put things on hold for awhile, but I have made some pictured progress. I think the overall helmet is beginning to take shape now.
Frontal:

This photos shows what I feel are the two biggest challenges-
1. These dang cheeks! Every time I try to work one spot, another gets wonky on me, or the circumerferencial shape goes out. Right now, I'm going to try gluing it all up, painting it solid, and see if I can get away with (gulp) sanding around the seams to make it look nice and clean with my paint. I'm hoping it looks worse than it is. I don't like the way that right cheek is flaring out.
2. The headband stretched differently when I shaped it to the ridge, so my perfectly cut 2" strip is no longer so perfectly 2". You might be able to make out the pencil line above the right brow where I need to sand down.
Right side:

It's a little tall in the center, but overall as smooth a curve as I can achieve. What say you?
With the ear in place, the tallness isn't quite so obvious.

Back:

The right side (from the back) looks higher than the left. I will adjust for this when I permanently glue the band in place. Right now, I just have skinny shims keeping it spaced high enough for a good fit.
I'm pleased with how well the rear plate fits. Haven't decided on my design for the key holes.
Left:
Nothing here that isn't really noted from the right view.

