Caddy Headliner

If you go to a local Auto Upholstery Shop, they can usually get you the headliner material and they have the glue that you can use to re-glue it with.
I haven't done a Rabbit, but I have done a US car or two. The issue is that the Foam material needs to be cleaned on the Cardboard, and I have used 100 proof Alcohol (paint supplier) to wipe it totally off. Test fit the material spray the board with glue and a little of the headliner with glue let it flash and then stick it on do sections at a time. Don't try to do the whole thing. If you go with a solid vinyl a hair drier will help to set the corners.

The solid Vinyl won't eventually pull away, as it is the foam that separates and causes the droop.

I wouldn't be so concerned with getting that exact saddle tan color unless you are trying to keep it all original. Fabric stores sell a generic foam backed material that is really great for early model Rabbits as a headliner. I used a gray tone in my Rabbit but I think they also had a light brown. I used spray on contact cement inside on the roof, cover all your seats and carpet first. Applied a layer on the foam and very carefully set it in place. You have to precut and fit the liner for this to work.