Found evidence that the sheet-metal patch one of the previous owners placed in the roof where the roof vent was not working when we arrived this morning. Nice puddle of water in the back floor from yesterday's rain. The windshield seal is leaking as well and there is rot in the windshield channel, so future plans are to pull the glass and repair the channel, then have the windshield reinstalled by the glass shop when it's all fixed and painted.
Girls helped me yank the front seats out and scrape up the scaly rust, then we took the drill to it with a wire wheel. Goose helped with vacuum duty again. Got it all scrubbed down, then we used our little electric pressure washer and some Purple Power degreaser to spray all the funk out the back doors. Tomorrow we will clean the rusted front floors with some Windex and spray them down with some rust converter spray paint. Apparently where the windshield has been leaking for some time, the front rubber mat with carpet insulation under it had been holding all that water on the floor and rusting it out.
The left side floor pad where the doghouse bolts down had rotted away at some point and the previous owner had patched that with a giant glob of orange RTV. So we will eventually patch that up proper with some new sheet-metal and a bolt. I also found out tonight that the seatbelt bolts where the seatbelt mounts to the seat base is the same thread as the seat hold down bolts on a 1996 Harley Springer when I was in a pinch for two bolts that were locked in the garage and I had left the keys across town.
My PC is acting goofy and won't let me remove the pics from my phone, so I will upload them as soon as I can.