From what I can see you have what you need to
install the headliner.
Remove the seatbelts. Don't mix the bows up. There are listing hooks on the very back bow that hook into the header panel above the window - I think I see them in your pics. Those hold the rear bow in place as you install from back to front.
You do not need the quarter windows in place. The rear window gasket hides the edge but there are 'gripper teeth' around the opening that actually hold the fabric in place. There are metal, u-shaped channels that run front to rear and cover the pinch weld and headliner edge (between a-pillar mouldings and sail panels).
Get yourself some headliner cement (or other appropriate adhesive) and a bunch of spring clamps and clothes pins. They'll hold everything in place while glue dries. Just takes patience.
I have a some pics here when I did mine:
Reassembly -1970 Plymouth Big Block Duster Project
Resto-Rick has some good instructions too:
Restorations by Rick Kreuziger - Headliner installation