Years ago a friend of mine used roofing "Bull Tar" on the inside of his doors as a sound and vibration deadener. Seemed to work as I recall. Anyone ever tried it . I'm at that stage of assembly.
Rusty,
I wrote an article about noise & heat reduction that I employed in the restoration of my Victoria. Send me your email and I will send it to you.
My technique uses inexpensive materials you can buy at Home Depot.
Most big box stores sell a foil coated bubble wrap looking product. Most have a self stick adhesive. The cheapest have no stickum, but a 3M spray adhesive will do the job. I bought a product, similar to Dynamat, Noico 80 mil Car Sound Deadening Mat 36 square feet for $1.78 per sq ft shipped. It is a heavy foil backed by a thick tar like adhesive.