Thanks for the input, guys. I haven't yet weighed the vehicle, but I've decided on a couple of radical changes:
1. In the rear, the firewood will be hauled in a plastic carton secured to a rack that will replace the bumper. I just need to find the right plastic box.
2. The shelter parts, the heavier part of the load, is almost certainly too heavy for the rear, whatever the numbers turn out to be. So I plan to design a rack that mounts using the front bumper bolts and swings out
in front of the bumper (not replace it).
Here she is in camp:

That shade canopy is strong and effective, and will stand up to the wind when secured to spikes driven into the ground.
But it is heavy!