What about removing the stained glass and replacing with traditional windows?

I think I would keep the top part of the window and replace the bottom sections.

I kinda like it, in a funky way....

Replace--try to remove without damage and sell on EBay

If you don't mind the top, replace the bottom with glass frosted to match the density in the top. Otherwise, I'd just bite the bullet and replace the glass in the whole thing. Completely worth it, and not as expensive as you might think. Otherwise, get curtains on a tension rod and cover the bottom piece.