so could you state that any headliner could be used in any type/year ?
It looks like it doesn't it, an early liner in a later car will have a seam where there isn't a bow, unless you add an extra bow (but that should still come out OK). A later liner in an early car will mean not using one bow (ditto).
I remember doing my '72 'cuda the bows did sort of find their own places in the various holes, somehow.
However, there are also differences at the sail panels where some cars have a liner which comes further down.
As it happens I have recently fitted a good '70 'cuda roof and side rails onto a '74 'cuda shell which had a totally shot away roof, so we shall see how that all works out !!