RE rear bows:
Difficult with overhead and restricted space work, the side slits
(listings) needing cuts in bow pockets is where
experience really would help .. .
Without removing windows, I used an added 'molding' to conceal glued window area. ('molding' is black foam garage door seal - handy for many applications)
When I replaced '61 't-Bird" roof headliner, rear most bow had two additional thin wire supports from rear window metal flange to the rear most bow. This held rear bow in place at proper position.
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have fun