I have to admit that I'm fascinated by this thing. I have both an RB system and a Nikon system, as well as LF lenses. It looks like you could use this to put either the LF lenses or RB lenses (with an adapter) on the front, and either an RB back or a Nikon body on the rear. Unfortunately, most of the pictures embedded in the text aren't coming up for me (is everyone having that problem?) so it's hard to tell just how useful this thing would be.
Having said that, this gives me some ideas for building a system like this out of my Cambo monoral (a system that doesn't see much action these days). I already have a 6x7 back for it, so all I'd really need to do is to build an adapter to mount the Nikon on the back, a lens board that could hold the mamiya lenses on the front, and a bag bellows so I could get the standards closer together. I have a short extension rail that I could use...hmmm...it's dangerous to get me thinking this early on a Sunday morning!
(Since I've finished both restoring my Korona Pictorial View and building my 4x5 enlarger, I've been looking for a new project. Maybe this will be it!)