The eye bolts on the frame of my 56-3200 are 4 and 5/8 down from the under side of the flat side of the top rail; you can measure from just inside of the curled edge. And 1/2 inch in from the side edge. They look just like the picture you found. I think the most important part of the location is that you need to make sure that they do not interfere with the tailgate piece with the long slot. As you can see in the picture they are pretty close and mine have only about an 1/8 inch separation. Good luck.
