Looking at the numbers posted here I can see a few ways to save some time if the condition of the frame is such that you do not need to pull it entirely out from under the body. The approach that I have documented elsewhere in these forums for doing a shell on floor replacement takes a lot less time for building the supporting framework, no time to lift off the body and no time to set the body back into place. By Kevins's accounting that could save nearly 40 hours off of the full body off approach he took. Also I found I was able to use the body itself as a template for the shape of the curved ends. I made a patern out of stiff poster board by cutting it until it fit the curve of the body as it set in place over the old floor. I did first check to see that the body at least was centered over the frame and that the side was not unusually bowed out. The front curve on my AS is not the same as the rear curve either by the way. All of the floor panels down the middle of the AS are the same overall width so I was able to cut them all to the same width(once I figured out a good place to get an accurate measurement).
Working on a sloped driveway is indeed a pain. My driveway drops about 9" per 8' of run. My AS is jacked up to about 3' at the back bumper and I can barely crawl underneath at the front end. Doing a full shell off approach would have been a real pain for me. I have been very satisfied with the shell on approach. For the small amount of welding that needed to be done I was able to call in a welder that makes house calls. I did want to sand blast the frame but found that my air compressor does not have enough umph to do it. So I knocked off all the loose rust with a wire brush and sand paper. I painted the frame myself with Hammerite anit_rust paint that supposedly combines with any remaining rust as part of the finish. The results are not as perfect as I would prefer but they should last a long time never the less.
You can check out some of the details in the following location:
Some information about a new material I am using for my floor
http://www.airforums.com/forums/showthread.php?t=11818 (title = Body and banana wrap on floor replacement technique.) Look especially at the first post where I added a drawing. At that time I did not fully understand the u-channel/c-channel construction.
http://www.airforums.com/forums/showthread.php?t=11814 (title = Shell Off vs. Shell On Summary) Look especially at my detailed progress report in post number 74. The bracing that I used there works great and does not require all that much in the way of materials. There are photos in my gallery that go along with that report. The technique does not require lifting the body entirely off of the frame.