Welcome to another tarheeler! If the roof is as solid as the rest of the cab appears, I'd straighten it rather than replace it, would be easier and and get around a lot of potential perils. If you need someone to fix it (or replace/chop it) for you, let me know. See my new topic "off topic darkside values" for a link to pix of same era COE (Chevy sorry) that just sold at auction for big bucks.
There are several nice bonus built F350 COEs on here done different ways.
I went to NM to get a rust free truck, but I was able to drive mine back to NC. It's well worth spending the extra money for as solid a starter as possible in the long run.