Replaceing a headliner with the larger ear muffs in a 66 with a new headliner and smaller ear muffs. There appears to have been some type of material glued & or attached to the metal of the interior side of the sail panel area of the body to act as a sound deadner or air blockage panel to block air and noise from the trunk area, that the headliner when installed covers. Anyone know what it is or what it looks like? Thanks,