I've been slowly working on pulling the interior wall panels. Nothing like an hour's work swinging a hammer against a cold chisel breaking tack welds and grinding off stubborn screw heads.
I've also been in something of a planning mode for next season, while waiting for winter to set into attack the Asphalteum™ (If it's as bad as NWS and Farmers' Almanac are predicting, the cold will definitely help). Once the floor's up, I've been thinking would it be worth it to run 4 longitudinal beams of double-stacked 1/2" ply ripped into 4" widths, 1" rigid insulation between them, then more double-stacked 1/2" laterally with 7' spacing and more 1" rigid filling the voids.
The inboard beams would be bolted through the existing mounting with elevator bolts, the outboard screwed in place with wood to metal screws through the floor or angle bracketed to the ribs through the chair rail. This would all be sitting on a layer of acoustical barrier.
Asphalteum is what Amtran/International/Navistar used to seal the roof panels and attach the fiberglass batting insulation. Really nasty stuff to remove.