Have a cardboard type headliner help

[Steve Agrella]

My 74 duster headline is sagging a bit in the middle other than that it’s not bad.
Are there any tricks to flatten the sag or bowed area out, I can recover it and put it back in.

 

[zkx14]

hmmm, usually the dome light holds it up...

 

[Steve Agrella]

Yea it got a warp in it just in front and to right about 18 ins