A full up restoration of one in that condition is actually tough logistically. The rust on the hasps is one issue, and availability of rivets to reattach then to replace or re-plate is another...
If you simply want the paint ti be nice again adn can live with a certail level of "Patina{ on things like the hasps, thats a differnt story...
that paint is near identical to Rustolium Hammered grey. so sanding it out, removing any small dings, piiming and painting is straightforward. the only real trick to hammered is getting it on thick so I like to paint that one surface at a time, level...
It's simple to refresh the paint, the hasps are the sticking point. I'd work those over with Nevr-Dull and see where you are BEFORE painting or even paint prep, and if they are good enough, mask them off and go for it...