I have a 1968 Winnebago 219SL. I am replacing the wall panels without removing the insulation. I have found out that they are polystyrene and cannot use contact cement.
I called Winnebago and was told I needed to use lamination adhesive, they however do not know of a supplier in California.
I do not know exactly what lamination adhesive but it sounds like the stuff I need to glue my new panels to the existing polystyrene insulation.