As I said above, I found a firearm thread that talked about different coatings. Came across DuraCoat which is available in an aerosol can.
https://www.duracoatfirearmfinishes.com/ I think I'm going to order some swatches to see which I like. This may be the easiest route for me to get a good coating on the window frame.
The air dry Cerakote is definitely a good choice. I might actually be the best choice. I don't have the spray gun for it though. I'm going to investigate some of the cheaper options for guns and see if I can make my little pancake compressor work without going too expensive on the components. If I was going to be coating a lot, I would invest the expense of a spray gun, etc. I'm just trying to do these little items for now though.
Thanks