Mike! I have one of these. Pretty much the same story, shop didn't even know if it worked. I have no manuals or anything. And my interface is all in Japanese. If you see this message reply and I will figure out how to get in touch with you.
Does your machine have the Mitsubishi Meldas M320 control? I just purchased the same machine and am getting ready to set it up with DNC. I was wondering what you use to upload programs and or drip feed?