The problem is deciding where to measure from. With all the curved surfaces, I was having flashbacks to non-euclidean geometry.
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I used the post by glwood above as a starting point, mainly the 5/8" shown, but even that is confusing because the edge it is measuring against is curved. So do you start with the part on top where it is flat, which is kind of like what the image shows? Or do you hold a tape measure against the edge, which will touch on the bottom of the edge that is further out? I thought I had it right but ended up being way off on my first attempt.
Once I got the passenger side correct, I took a picture of it, then looked at in on my phone while sketching with a pencil on the driver's side, to try to get it right. If I had to do it again, I would use the same approach with the two pictures I posted of the driver's side. It should get you close enough, and if there is an error that needs corrected, the grommets can still make it look nice.
Also, the grommets don't have to be purchased from GraBar - they can be found in many places, here are some on ebay that I bought:
https://rover.ebay.com/rover/1/711-...0001&campid=5337789113&icep_item=251520709145