I removed my interior endcaps along with everything else recently. The insulation was in really bad shape and there were lots of mouse trails in it. I did have a hard time taking them out, but the really hard part was taking down the ceiling panels. In mine the two panels that make up the ceiling are buck-riveted together and installed as one piece, which is about seven feet by twelve feet.
After removing all of the insulation the "old trailer" smell was completely gone. It hadn't been very bad, but the difference was noticeable. I'm installing new foil faced insulation everywhere.
68 twind and airstreamjudy, the dents you have can sometimes be pulled out part or all of the way. I've heard of people using suction cups, or hot-melt glue and sticks to pull dents on upper panels out. It may leave creases still but if you can get most of the dent out it looks way better.