I just finished the headliner (and windlass) install. It all went well although spread out over a long period because of distractions. The only real problems encountered were:
1. Needed to replace some of the tack strip materil. I used a vinyl but on the next one I would search harder to find the original fiber or paper based material. The vinyl resisted some tacking and did not seem to hold staples as well has the original 65 year old stuff.
2. l did not measure carefully where the dome light wires and sun visor screws come through the headliner. After the liner was in had a hard time finding those locations. Worked out OK but took way more probing than it should have.
3. On the PV444 the headliner uses a cable around the rear window. I could not find a good place to secure the ends and finally just tied the two ends together with a wire loop.

On balance, much easier than I had expected.