I have 1976 MCI 5b Challenger and torn off the headliner due to stains. Once I got it the headliner down I noticed there was vent/slots in the front ceiling covered in glue. There were additional holes in the inside layer of ceiling due to what I think are the bolt holders for the old overhead baggage binds.
Each place that had a hole, there was black stains in the headliner. Question I have is - are these slots needed? Are they a part of some ventilation system?
Can I sealed them up?
I am not familiar with the bolts you are talking about, but I can't see that there would be a problem sealing them. You will get enough ventilation from other sources even it they had had some purpose like that although I doubt it.