Jim:
I was glad to see you enter this discussion as it sounds like you have some experience with these roofs. Do you remember what order the parts were put back in? My main concern with reinstalling the roof is if we start at on end after putting on the three edge locking strips will there be enough "Play" in the interlocking panels and ribs that we won't match when we gwet to the other end.
The one thay took off is light also, 26 ga by my estimate and in pretty good condition for being 75 years old. There is some red rust but almost no white rust which I would have expected,
Let me know your experiences
Frank