Thanks to everyone for their thoughtful input. I completed the repairs as of yesterday so we'll be rolling again this weekend, in time for our reservation in Plymouth CA.
I ended up doing all the repairs myself. Fixing the floor was time consuming but not difficult. I cut out the damaged area including about an inch of material that rested on the frame. Then I glued in some 1/2" exterior plywood that I on hand with construction adhesive. Then, just to be fancy and because I had some laying around, I glued down some linoleum to complete the repair (doesn't match the rest of the floor, but its' under the fridge anyway!) Since part of the new wood is supported by the frame, I was able to drill one hole through new material and two more through the adjacent original floor. I inserted 1/4" stainless steel pan head screws with fender washers (under the head of the screw on the inside). These went through a piece of 1/8" aluminum plate that I added as a "scab" over the repair which I secured using fender washers and aircraft nuts. I This got sealed the edge of the plate with Henry Wet Patch Roof Leak Repair. I don't think I will be having any issues with this repair as it's now tougher than the original floor and more waterproof to boot.
It turned out that the damage to the refrigerator was mainly that the side mounting pieces and the bottom trim were broken. Other damage was just some tears and dents to the insulation on the bottom of the box - easily resealed with some duct tape (the silver foil kind, not the fabric reinforced stuff).
Replacing the trim around the fridge was simple enough, although Dometic did not make it easy. My local Camping World ordered the parts for me but for some reason, they could not get a match for the color. To my old eyes the trim looked "black-brown" but that was not an option, nor was "black". So the parts guy and I agreed that the Grey they offered was probably the closest match. But we were wrong. Grey was plain old grey - not even dark grey. My solution was Krylon Fusion paint for plastic. The satin black was close enough that it does not distract and I'm happy with the results.
I used some weather strip purchased at Ace hardware to seal the 4 trim pieces around the fridge and that was that. Re-installation was made a bit easier by setting some cardboard between the fridge and the side insulation - and withe some help from the wife who pushed it into place while I guided it from the outside (so that it wouldn't snag on anything.) All-in-all it was a piece of cake.
So total time for the repair not including watching videos, reading this forum, asking friends etc. was probably about 6-8 hrs. Most of that was measuring, cutting and then doing it again - with the correct dimensions. Oh, and trying to get the right parts. The Camping World guys in Roseville did as good a job as they could, but it would have been nice if Dometic had been a bit more helpful on the color.
All-in-all not to difficult a job - but I'm glad it's done.
2013 Flagstaff T12RB
2005 F150 4.6L V8 2WD Supercab