Cork sheet/tiles as insulation in old, old Mirage 30 - good idea or not? If yes, what adhesive to stick them with? (All old foam-backed head and side linings crumbled like Crunchie)
Use proper sidelining carpet type material, you can even use cheap, unbacked, normal carpet. Stick it on with spray glue. Now done 2 boats and both looked good and stopped dripping. For head lining, try to fit it onto thin (3mm) sheets of ply screwed onto thin battens glued to the glassfibre.
I used an insulating material for cars called armaflex under the head lining when I did this job last year on Efaki a Mirage 28. The difference in temperature both in summer and winter is significant. I used a petrol based glue from Henkel that after aplication didn't smell at all. You can see the procces here: http://www.sailingboatefaki.gr/New%20Uphlolstery.htm
Armaflex or Korex (which is cheaper I think) and the like closed cell flexible soft foam sheets are the insulation materials of excellence - both quite pricy though if a biggish area to cover.
Just to update - did some cork tiles, looked like vertical kitchen floor, so bit the bullet and re-lined in foam-backed vinyl, new panels, the lot - looks great, but only just finished, and, despite respirator thing from Hawkshead, felt pretty toxic whilst doing it!