Here's a bunch of pics with some dimensions. Couldn't find anything to measure the angles with so stopped for now. After these initial pics you may decide to buy an original (I know I would).
The metal looks to be 1/16" thick.
The first two pics gives you an idea of the shape. 3 metal bends plus a piano type hinge (upper left hand side).
The small piece of metal on one side of the hinge bolts to the cab with 3 bolts, washers, lock washers, and a nut. It is 1" from the center of the hinge to the edge. The entire panel is 23.5" wide.
The metal on the other side of the hinge (which makes up the entire rest of the panel) has the first bend (from the hinge) starting after 5.5".
There is where I stopped on measuring for now. More pics are coming with things you'd need to do if you want it authentic. If you're still serious I can get more measurements.