3D Printing
I took some rough measurements of the hole size to attempt to get a good press-fit for the hub.
Using TinkerCad to draw the hub and a MakerBot 3D Printer to print it,
after some fine tuning to get the dimensions just right, the resulting part looks good and is fairly solid.
You can see the 3D Model here.
Here is what it looked like as a drawing

After some sanding, priming and painting the final hub is shown on the right. The left is an unfinished version and the middle was a failed attempted at painting.
This is what the bottom looked like to cover the small bolts and press fit into the wheel |
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Here is the hub installed. |