Well, here is bike box wheels 2.0! I borrowed from the original Aussie design and made some, what I consider significant, improvements as follows:

1. The fold out "outriggers" have been moved to the inside of the bottom angle for better contact with the box.
2. The attachment points for the straps on the wheel assembly has been moved to the end of the "outrigger" braces for more leverage in holding the wheel assembly to the box with the tension that can be exerted by the straps.
3. Slide design was changed to smaller angle to eliminate the need to find telescoping square/3/4 tubes. It was hard enough to find the other aluminum stock.

Materials:
Qty 2 - 2" x 2" x 1/8" x 4"- Large angle - Metal Supermarkets
1" x 1/2" x.090" - Rectangular tube - Axle carrier. - Metal Supermarkets - Couldn't find .062" wall so had to file the nuts down to fit!
Qty 1 - 1" x 1" x 1/16" x 7" - Slide angle - Lowes or HD
Qty 4 - 1" x 1/8" x 3-1/2" - Folding outriggers - Lowes or HD
#8 flat-head screws with nylock nuts and washers/lock washers as appropriate
Qty 2 - 60" main diagonal strap - Gear-Aid 60" straps from REI
1-1/4" split rings - Top corner harness - hardware store
Qty 2 - 26" x 1" nylon strap - top corner harness
Qty 2 - Used skateboard wheels
Qty 4 - 22mm x 8mm x 7mm skateboard wheel bearings - Find ones that are rubber sealed on both sides
Qty 2 - Skateboard wheel bearing spacers.
Qty 2 - 5/16" wingnuts
Qty 2 - 5/16" x 2" - Threaded rod - axles
Qty 4 - 5/16" Nuts - Axle assembly & holder.

Photos: