After mocking up the boom I set her on her feet. Wow, almost had rims string on the bench the tires were so squished. And that's with the stock foams.
So been asking around - see previous posts.
So This is what i did
Dissassembly,

Donor wheels with hard foam inserts

Slice part of the carcass off


Wrap 2 side by side in craft foam sheet - test fitted strip in side tire to get correct size. Had tried tires along but did not fill inside space.
And then squish it all inside. Good thing these tires are soft.
Then used clamps to clamp together.