Design / Specs
Very similar to the Pololu 80x10mm wheels (see http://www.pololu.com/catalog/product/1434).
Wheel is 76.5mm across (80mm with a "tire") and 10mm wide.
The mounting holes are for 4-40 machine screws. The top and bottom holes are spaced 3/8" apart horizontally and 16.5mm apart vertically. The middle two mounting holes are 1/2" apart.
The shaft hole is "D" shaped, 3.0mm in diameter with a flat 1.0mm away from the center of the hole.
I would suggest 3D printing these guys. If you can print support material print the Poleel80x10mm.STL. If not print 1X of each of the Poleel80x10mmTop.STL and Poleel80x10mmBottom.STL and then glue together.