The roof panel looks pretty good (compared to the rest of the truck ). Basically, the damage is a thin line of rust-through between the drip edge and the rest of the panel all around both sides and the front. Imagine taking a new roof and only welding it on along the rear seam - that's what I have. The roof has a few minor dents in it and is rusted - but not through except around the front and side edges.
I was considering removing the roof panel by cutting it off at the rear seam with a cutoff wheel. Then I would trim the panel around he sides and front and weld in strips of metal to even out the three edges. While I had it off, I could really clean up the drip edge and the section of the inside upper cab near the drip edge. Finally, I would set the roof back in place and weld it to the drip edge and across the back. I had thought of inserting a steel rod in the gap made by the cutoff tool so I had a nice, continuous surface when I put the roof back on. As already mentioned, the welds in the drip edge get ground a little and covered by seam sealer.
Mike, what would I have to watch out for if I did remove the whole thing? Since I've got to cut out and replace a strip of metal around both sides and the front anyway, it just seems easier to take the panel off rather than work with it on the truck. Remember, there is very little (if any) connection between the roof and the cab on either side or across the front.
I've also been advised to just look for another cab. That's a last resort if I absolutely can't fix the one I have.
George, when I removed the roof on a 56 , the entire cab tried to fold up. The noises it made were one of pain, poor cab. I just did it to find out what would happen as I had a few cabs. I also tried removing a dash and that cab folded and twisted before my eyes. The roof on that cab went to Nixer and he is not going to use it and it is perfect and whole. Jonathan
In my first reply I did not understand that your sides over the doors were also rusted apart. That kinda changes my thoughts. Now at this point I would go ahead and remove it asuming the rest of the roof in in fair to good condition. Once removed I would add my filler on the remaining cab portion, actually adding a bit more than needed folded in a bit to alow the roof section to silde over top. this will allow you to fit it up betterwhen replacing. then after cleaning the roof edges I would it back in place sliding it down over the new edges that you made on the cab tops, as long as you don't cut into the contours of the roof it should hold its shape pretty well.
This is how I would go at it. At this point what do you have to loose.
Just my thoughts