Does anyone have details for making door opening braces for E-body convertibles for a rotissorie?

Attached are pictures from the Clark Classic resto site. They appear to be tube steel with threaded adjusters, perhaps Heim joints as well.

The appear to bolt at rear seat belt bolt, top mount area, and some crazy brackets at the dash area.

Want to have the doors in place.

Any detailed pictures of the end attachments, brackets, etc would be appreciated.