Well, I went to bolt on the 15x6 Mopar steel wheels to the trailer, and they end up being tight against the framerail! So, I went to Plan B, and took two of the 50-year-old chrome reverse wheels and whitewall radials off my lowered '68 Dodge D100, and bolted them up to the axle...they look great! And, they have nearly an inch of room between the tire and the framerail, so they are going to stay on the trailer. This gives me a good spare for both my Dodge pickups, from the other two chrome wheels and whitewalls, as the lowered truck is getting new 17" wheels and tires, anyway!
I also have the wood floor mocked up on the frame. This is going to work out very nice. As I have a good bit of ground clearance under the trailer, I'm thinking about having David, my welder, build an 18" x 44" x 6" storage "locker" under the rear part of the trailer frame, which would be storage for tools, a small jack, spare parts and miscellaneous bits. It would be accessed through a full-width drop-down door that opens to the rear of the trailer, under the hatch. This storage area would open up the area under the rear hatch for more things that require ready access. Since the axle sits back somewhat on my trailer, any weight issues that might have been caused by this box, should be pretty much moot here.