A good glass shop can fabricate window screen from just dimensions or by using another of your windows
as a template. But they may be stuck with the thickness of the window and screen channels not matching the aluminum stock that they make the screens from.
I would pull another of your screens and take it around to all the glass shops to see if they can match it.
If they cannot then you will need to get creative and think about who you know who likes to make stuff. This could be an easy winter project for them, and earn them a case of beer from you.