Replacing window frame

I had a client's window blow out in a wind storm and they want me to rebuild the window. It is a fixed window that was installed to protect a stained glass window and as you can see from the pictures, one of the sides bent. I am looking to identify the parts used to make the frame, so that I can either replace the bent side or build a new frame similar to the current one. The frame is around 27" long, so I anticipate having to make this frame custom, but the aluminum is 5/8" wide and 5/16" thick (where the window and gasket are placed).

Thanks for your help.