George,

I found a manufacturer in Europe. I looked very hard for a nema 23 dual axial 0.9 degree stepper with 1/4" shaft, and it seems the Chinese do not make them at all! But I did find a company in Germany, that will only sell to businesses, not individuals. I bought one. Shipping was $70. Interestedly, they sold a 10mm damper plate to stop vibration transference for $14, so I got that too to test it out.

Peter