Jorb,
Thanks for the idea for the floor and the link to the old factory photos!

I notice the holes in the wear irons line up with the holes in the rim of the body. Do any of the wear iron bolts go through the crossmembers? All of them? None of them? I think there are more holes in the wear irons than there are crossmembers unless I'm missing a crossmember of two.

I also have two cross members that have only two large head carriage bolts at the ends that come through the floor just outside the frame rails and just inside the outer most wear irons. (I think on some years these are the bolts with the washers that have off-center holes) There are no holes in these pieces to bolt to the frame. Am I correct to assume these just sit on the frame rails? I'm at a loss as to why the floor is designed like this but I'm sure there's a good reason.

David