Ken,

If your existing canopy is just a canopy with no frame outline molded in, you can make a canopy frame. First coat the canopy with PVA release agent and then do a fiberglass lay up over the canopy. Once cured, pop the fiberglass frame loose from canopy, draw your frame work outline and trim to shape. The PVA release can be removed from the canopy with water and will not damage the existing canopy. Just make sure to get the canopy coated good.

If you opt to make it functional you will still need to do some internal structure, side rails, front & rear frames, etc... to stiffen it up.

One more pic, just because it's cool.