make your own.
Not trying to be funny, but if you cant find some ready made ones, it shouldn't be that hard to make your own. Find something with the approximate radius. A length of pipe, an old (empty) oxygen cylinder. even a tree limb might work. Form the sheet metal around it. If you find the thickness of the metal you chose is too thick, heat it with a rosebud torch. If using an empty oxygen cylinder, you'll want to open the valve all the way. If you need a lip on the bottom edge, notch along that edge (only where it's radiused, every 1/2 inch or so & fold the edge over with vise grips & weld the little seams.
