Any advice on restoring Steel Casement windows?

[TheFixer]

I've done some years ago, and used everything from a palm sander, wire wheel, heatgun and sanding by hand to get to all the areas. Your hinges look different than mine since they are on the side. Is the hinge pin removeable? Maybe you can remove them and replace the pins when you put them back int? Just a thought, it would make most of the job easier.

As far as screens and storms go, mine has 4 holes in each window opening that the screens get clamped into. You can probably have the AL stype screens and storm glasses that any good hardware store can make to size for you. If you don't have the threaded holes, you can make a jig to drill and tap them. There are varius styles and sizes of screen clamps out there.

We had screens, but made wood storm windows that used the screen mounting holes. The benefit is you can make them yourself if handy, and they cover the steel. Not sure where you are at, but the steel frames get very cold and can even freeze up if humid enough. If you don't care about replacing the glass, you could always sand blast the outside. Not sure you would want that mess inside.