That truck is a 79.
Roof fits 72-80.
You could change the outer skin and drip rail from a parts truck.
It will most likely need the inner skin and possibly the header too.
If you are capable, it's not a difficult repair.
Find a junkyard truck, saw through the pillars, bring the chunk home and carefully disassemble it.
But look at the floor and rockers and decide if it's clean enough to do the work to, or if you should swap a cleaner cab on.
There trucks are super easy to work on