If the old onza pro hub measures up the same as the 2012 onza hubs. Which I hope they should be close if not the same.
Old onza hub should measure dia, 30
And c-f 32 on both sides. Unless its a disc model.
You could make it quite a lot wider.
I used c-f 40 mm both sides
And with that you will need a flange dia of 32 mm to use the same spokes.
257 mm spokes