ive got a hasbro and have been putoff by the ears
Yeah, those are pretty... impressive... earcaps.

Mine are sitting on my "free to good home" pile. *chuckle*
Anyway, UPDATE! Cuz, y'know, I've been working on this thing and stuff...
And remember -- when I say "right" and "correct" I'm referring to the measurements of the original Boba helmet that I'm using as base inspiration, not saying it's the only way to do things.
First, capping off the last picture of the helmet in progress, the filled in and smoothed over dent:

But before that, I'd superglued strips of sintra to the inside of the dome seam and epoxy-puttied the edges to reinforce and blend:

I also filled in the existing "turn signals" and placed correctly-shaped ones the right height above the brow band -- this is them mostly shaped and still in need of a little cleanup:

And I added a 1mm strip of sintra to the bottom edge of the brow band to widen it to the correct 13mm:

And prepped the leading edges of the back skirt to anchor the new side pieces:

Which, speaking of:

Glued in place on the right cheek piece:

From the outside:

I also glued a strip of sintra along the inner edge of the mandibles to help anchor the reshaping:

And an assembly of scrap sintra bits at the bottom of each "tusk" to extend them to the right length:

Then epoxy putty to reshape the curve of the cheekbone to something more like the original:

I built up the lower edge of the visor opening, as well, but seem to have not taken any close-ups of that while I was doing it. Thought I had.

At any rate, here's the left side glued on with the join to the back skirt puttied over:

And the whole shebang reinforced on the inside:

When I cut the cheek pieces off, I did so straight level, and shortened up the side of the upper part to 8mm, so once I added the strip of sintra, the corner of the visor opening is the correct 7mm high:

Then we get to more stuff I thought I took pictures of -- the second laminate layer of side pieces cut from 1mm sintra and glued onto the first, and then the epoxy putty over that to get the get the depth and contours right. Here's the current result, partway through cleanup:

Those reference lines mark the front and back edges of the scratchbuilt earcaps, and the midline reference.
If I do another one of these, I'd move the corners of the visor slit and the back edge of the cheek insets back several millimeters, and -- depending on what that does to the mandibles' positioning -- maybe leave off the vertical strips on the insides of the tusks. As I have it now, if I were to take those off (which I might), then the vertical part of the T would be the correct width. Since it's only a millimeter on each side, I'll probably just leave it as is.
Which is currently still in need of a bit of cleanup and finishing off the keyslot opening, but:

Getting there...
--Jonah