Bending aluminum for window frame

I know this question does not directly relate to a particular airplane but this vehicle was made by a airplane manufacture after WW II in France. I feel this particular detail was also used on airplanes. As you can see from the attachment, an approximate 1/2 inch by 1/2 inch channel sits on a ledge and enables two plexiglas panels to slide back and forth to allow air into the car. Access is by way of a hatch. The steering wheel looks like it came from the airplane. The problem I have been having is to bend the thin aluminum channel around the four different shaped corners without warping. I have tried all suggestions without success. If you know of a craftsman/company that is capable of produce good results please let me know.
I very much appreciate you help in this matter. Attachment 4792

Hi
My best guess would be an aircraft workshop, where they maintain planes. Otherwise they may here have contact with someone who can.

We have a super auto craftsman in Denmark: http://www.n-av.dk/handcraft.html

Good luck with the fun project

http://www.tinmantech.com/

I'm not so sure it's bent around the frame. I think it may be cut to shape, then put on. I have used flow forming for parts of my project and it works well with thin enough aluminum.