Replacement...
I used to have an '83 First 32 that had the same problem. Lots of folks do if you check the archives, too! Anyway, I found headliner material at www.sailrite.com, and replaced the old stuff. Use 3M super trim adhesive spray to install the new material, after removing the old stuff and cleaning the residue on the hull as much as possible. You don't need to get all the old glue off, but you need to get the loose and old foam residue off. I just wire-brushed everything and most of it "powders" right off. Then wipe it down with Goof Off solvent, or any other solvent that will leave the surface free of dust and loose residue and you'll be ready to glue the new stuff up. Its a big job, and to do it right you may have to have a canvas or upholstery shop sew the finished edges on the new pieces, but its the only way to effectively restore the headliner. The old stuff simply will not re-adhere no matter what you do!Good luck!Tim