Komura Uni Helical Focusing Unit II for Bronica

I have a Komura Uni Helical Focusing Unit II that fits my Bronica EC. I intend to use to mount some barrel lenses I have and am wondering if anyone knows what the thread size/pitch is at the front of the unit where I assume Komura lenses would be mounted. It looks to be around 69mm. Any help greatly appreciated.

I don’t recall the thread, but I had one at one point with the three Komura lenses that I used on my S2A, and I had a Schneider 500mm Tele-Arton mounted to it with a tube made for the purpose. It’s been a while, but I think SK Grimes made the adapter tube.