We painted the windows and cleaned the glass til it squeaked. 
These windows were designed very simply with regard to their hardware. Not a hinge in sight! Each window has just a bronze top latch, and when the top catch is released, the windows lean inward against wood stops.

We were able to restore all but two of the latches. We soaked them in a rust remover, and then applied a primer coat and then a brassy-looking top coat. And finally ... it was time to pry the plywood off the openings, and install these sweet! hand-crafted, true-to-the-era ... beeeuuaaatiful windows! 
And now ... check out the before and after shots!