The Hero helmet should only have three indents and then be flat the rest of the way out, but on the right side of your helmet (as you look at it) there is a small fourth indent
The cap seems to have a larger forehead portion than the distance between the front and back trapezoids. Even with camera warp towards the edges I think this is still the case, and I think it would help a lot with the overall look to know exactly where the differences are between the Hero and the Stunt.
The triangular area here is straight out flat. It seems like yours is too and it will probably stretch out when you attach the ears, but the temples should stretch out all the way.
Your third tooth looks a little big, but that's also dependant of course to how it is cut out.
I don't know if it helps at all but it is like the chin is in an underbite position towards the left. The right side here I'm able to see the parts both below the teeth and above the teeth.
The right side with the same angle it's not possible.
The middle tooth starts more towards the left fo centerline.
Here is is easier to see the actual difference of the underbite towards the left (as you wear the helmet). Here you also see the middle tooth being off center.
I don't know if some of this helps you at all, if not just take it as affirmation that you've done things right already!
Here's a gif in which I aligned the nose bridge above the teeth with the both images and the eyes. We can see when switching between them the the tears in my Hero bucket rotates clockwise, and bottom right corner of the trap isn't as rounded off, and the shape of the mouth and chin almost squishes into the face a bit more, just to name a few things.