So here it is, pull #1, aka my new Rex helmet. I'll try to run through the changes...
The fin starts further up the forehead (think receding hairline). The flare on the sides is less pronounced. The ear bumps are bigger. The flared bottom edge is not at such an extreme angle. The chin is shorter.
The undercut around the bottom edge is bigger. This means the head opening is quite a bit smaller, but it makes for a more solid feel, and exposes less of your face underneath. This change could be rolled back for someone with a bigger head by just cutting the opening larger.
The side really shows the shortened chin. The back is raised up more... a lot more. I probably took an inch off the bottom rear edge, with all of the reshaping that comes of something like that.
You can also see the change in angle on the lower flared edge really clearly here.
The RF topper is now tapered on the front and back. It used to be Fett style where it was angled in the front but a straight line on the back.
I also extended the part to the left of the stalk about 1/8", making the whole thing longer.
The changes all came from just having more reference materials now than when I started.
I'll be painting up this one tonight / tomorrow. Fun fun fun!