As an update, I purchased a SINAR 140mm Converting SINAR Shutter adapter plate on eBay, it look like it should attach to the Sinar board on my Ebony.
Then, I purchased a complete Sinar x with a Sinar/Copal shutter. It looks like one of the more recent shutters because it goes down to f4 instead of 5.6. I bought the kit for about the price of what shutters appear to be going for.

Now I need to find a Sinar board with the right size hole and it looks like I’ll need to create a spacer because the lens extends about 1/4in psat the flange and will run into the shutter.

I still have a lot to figure out but I think I’m getting there, my wallet is getting thinner anyway!

www.timeandlight.com