Here is the latest iteration of my part.

When it is completed, it will be an accurate drawing of the “gas tank support” of a C2 Corvette. I still have to place the mounting bolt holes, and input the actual measured dimensions. But, as is, this is roughly what the part looks like. As it is a parametric model, it should be a piece of cake to go from here to a fully accurate drawing.

As suggested, I drew the outline of the part as a polyline, then filleted the corners.

I could not find a way to input the thickness of the part only once. And, as this part is manufactured as a stamping, I did not want to place any measurements from a sharp corner to either the inside, or outside, edge of a fillet. Similarly, as this part is a stamping, the exact dimensions/centerpoint of the radii of the rounded corners are not critical to the function of the part.

I tried to keep dimensional constraints to a minimum, and utilized a lot of “equals” in this sketch, including the angles of the arcs.

Again, thanks to everyone for your help.