Those top pieces sure look like standard Bonnie pieces. It might be a little challenging on a windy day with the screen sticking up like that. But, it's never very windy in KC is it? <g> Check Ebay for a used screen. Maybe you'll find one that has the plastic in rough shape but you can't do much to those brackets.
A new, removable Memphis Shades screen or other brand is probably cheaper than new brackets (if you can even buy just the brackets).
