Almost all interchangable, 91-94 sedans used the square dome lamp whereas the 95-96's used the oval dome lamps. So using a 91-94 headliner in a 95-96 would leave a bit of a gap around the dome lamp unless you converted to the older style dome light. Also at least for the tan color and I think the blue color as well there was a slight color change between 91-93 and 94-96, so if you are overly concerned about the color that may be an issue. Other than that there aren't too many issues. - Peter
Get some 3-5 oz. woven glass, some 1/2-3/4 oz woven glass, and use some polyester resin. Push/pull or bend the foam into its original shape, and do the back side first with the heavier glass.
Lay the glass on the surface, and pour the resin on it. Use a medium to large paint brush and stipple the glass to get good penetration, and a spatula/spreader to remove the excess. You do not have to do all of it at once. If you use a minimum overlap, it will not affect the strength appeciably.
The polyester resin sets up quickly. Allow to cure. You do not have to sand the edges for adhesion. The headliner core should be fairly strong at this point. Make sure the inside is shaped right, and be sure there is no fabric foam on the interior. Then use the light glass to do the interior. You can do the interior with multiple pieces, because it is so thin you would not notice the overlap through the covering.
I reinforced an OCC headliner with 5 oz. carbon fiber on the back side, and you can almost stand on it.
I guess it really depends on what is actually damaged! Pics? or a better description of whats broken? I find it hard to believe they are all damaged in the yards as well! When you say damaged are you refering to the fact that the fabric has come loose and is hanging down?