So, Grigg, the idea of using just one of the wheels on the back instead of the dually makes sense, but what about the axle housing that sticks way out? Not sure how to shorten that. Its those little things. You are thinking orient the wheel like the outside one I am assuming to help with that.
I am currently working with wheelsmith on my half ton to get special, original looking wheels to fit over my front disc brakes. If I like their work, my plan is to set them on a new course... figuring out an original looking, single piece rim that takes modern radial tires for the big bolts. Their prices seem reasonable and it could very well be worthwhile.