Its only been two years after your post and Iām about to ask you a question about it! 
First of all like everybody else said , thank you VERY much for you great write up, It helped a ton.
I have two questions if you have a moment to answer (or anybody else), I really appreciate it.
I saw in your picture your power input and from the look of it Im guessing its a 12 AWG wire arent we suppose to use 10 AWG (for the 30 AMP) that the Hitachi draws with the 2.2Kw Spindle? I saw that in the manual. Please let me know if Im missing something.
My second question is about how to make the 6 Pin connector for the signals going from the Hitachi back to the MASSO, Any picture or document you can point me to to know how to do that connection?
In your picture I do see two wires (One red and one white) connected to, what I think is SN and SP. Is that the only two that needs to be connected? how would I connect the other side that is the 6 pin socket that goes to the MASSO unit?
Another guess is using this diagram: VFD/SPINDLE wiring schematic for Elite Masso machines
According to this,
Pin 1 = L (Ground)
Pin 2 = Input 1
Pin 3 = Input 5
Pin 4 = Input 4 & 6
Pin 5 = NOT CONNECTED
Pin 6 = Input 7
Its not super easy to understand the manual 