I've replaced all of the insulation with "Reflextix" sold
by most of the hardware stores.
It is essentially bubble wrap with tine foil on both sides. You can you spray glue like 3M "77".....but, it gets everywhere....
I eventually resorted to a hot glue gun and aluminum tape.
I have pics in my story.....1978 Boler
ln41211 under reno and mods