I did something similar. I used rope and tweet. No pics just memories.On my old 94 I bought some foam backed headliner material and used a water based contact adhesive that I applied with a spray gun. I had two people hold the corners of the material just above the fiber board and lightly pushed down in the center and worked it out to the edges.
It turned out great and looked just as good fifteen years later when I sold it.
I was just thinking about that job as I was typing this and remembered that I used some 1/4” closed cell foam and cut it out in the shape of flames and glued it to the fiber board before the headliner material. The material was black and you had to look closely, but you could see the impression of the flames. It was pretty cool for the 90’s.
All tweet trucks of the 90s smelt like a can of glue.