Craig,
That's an amazing offer. It's not really that I can't afford it, I am always value conscious.

As I mentioned above, the ESS/MB3 shows out of stock.

The UC300ETH-UB1 seems like it has similar functionality? Thoughts?
https://cncroom.com/en/product/uc300eth-ub1/

Just to be sure, if I get the ESS/MB3, or UC300ETH-UB1, that becomes my bob and I just attach my existing wires to it and the C10 goes away. Connects to my laptop and spindle runs on P1/P2 of the KBB. True?

And if I were to make the circuit you so generously shared, I can use it with my C10 and get the spindle going, but I would need to add a board like the UC400ETH to attach to my laptop instead of the old PC. Yes?

Mark