I figured out how to mount the "tractor trunk" with the suitcase weights (5 total) on the rear (the trunk is designed to mount without the suitcase weights).
I like having the trunk, I can carry extra weight, my regular chains in case I need them, a shovel, extra fuel, salt, etc. The trunk also dumps, and I drilled holes in the bottom for drainage.
I used a pair of turnbuckles to pull the top of the mounting bracket to the rear and hooked it into a slot inside of the rear tire, the bottom is bolt through the trailer hitch hole with a large bolt (not shown)
The ratchet strap helps to hold everything tight with no rattles or clanging from the weights