'28,'29 A closed cab - replace wood with steel.

Does anyone know of a link or site for replacement of the wood
structure with steel in a '28, '29 Model A closed cab?
I'm going to have a wood & fabric top to bolt on top,
but I want a steel structure to tie the rest of the body together.
I've built the "B" pillars so far.
Thanks!
Joe

 

Lookin' good Joe!

 

I would like to do the same with my 28-29 five window, if I come up with anything I will post it.