That's a really interesting design. I ve never seen one in the flesh, though I saw a review in a mid 70s mag' [before it seems to have sunk without trace].
That looks to be two 'Americana' type plate binding barrels. each pressing against a grove machined into a disk. It's kind of spademan meets gertsch [though I guess in the spademan the arms were 'pulled' together.
In the day there could be an argument for it with the load being measured close to the tibial axis [ish anyway]. I was pondering how it would behave with upward loads but the blocks the plate rests on would change the leverage & the pivot point in the system so it might make sense and get close to a 4:1 My:Mz ratio. The maths and engineering would have been a bit painful in the mid 70s but a 14 year old could probably work it out these days.