Cab corrosion and paint bubbles

Hey Everyone! New here on the forum and I'm hoping to get some answers about International cabs. Seems as though there is a lot of international cabs out there with at least some sort of corrosion on them. Typically I see this underneath the windshield on both sides. And on the doors around the rivets, and around where the grab handle is bolted onto the cab. Why is this? I don't notice it as much on the older, non-I models. The company I work for as five International trucks, all 5600i's, ranging from 2003 to 2007, that all have paint bubbled or paint missing throughout the cab and a rough spot where the corrosion is. The reason I'm wondering about this is because I want to get a 2000's model 9900 for a project truck. Can the cab just be stripped of all the paint and reprimed and painted to have a smooth surface again? I want to do an international for a project because it seems like everybody does a KW or Pete, and I wanna do something different. I'm thinking a 9900 and putting a small crawl thru bunk on it. And the usual big stacks, drop visor, hardwood floor and low ride seats.

 

What material is the IH cab even made out of? The hoods are fiberglass, I get that, but what is the cab itself? The bubbles in the paint and corrosion the trucks I see, at least the ones I'm around all the time where I work, I wouldn't really consider rust. In the spots around the rivets on the doors and where the grab handle bolts to the cab, I would also call it a reaction between two metal types. Maybe thats not true but its not really the typical rust you would see on a car.
As far as doing an International truck project, versus a Pete or KW, its just something different. That you don't see done. I have driven all truck brands, each have their pros and cons, and everybody is different in what they perfer. Same goes with engines and transmissions. I drove a 09 Pete 388 at my last job, with a 475 cat and 18 speed. Now I'm driving an 03 IH 5600i with a 500 ISX and 13 speed. Same line of work (quad axle strait truck) but two different animals. The peterbilt was nicer, more fancy, and I liked the C15 engine. The IH rides rougher, less options, and I'm not much of a cummins fan. They both do the job and I'm making more money working for the guy with IH trucks. Probably because his bottom line is bigger from not having a fancy peterbilt. Everybody likes something different, and I just think a 9900 all tricked out would be something different. Right or wrong.

 

So can the oxidation be sanded down smooth and reprimed and painted? Or will it some back through the new primer and paint right away? IH must have cheaper aluminum or cheap paint because I see it the worst on their trucks....