For those interested in the mecanical aspects of a Perfecto restoration, I cleaned, blasted and assembled the inner carrier of the Perfecto and placed it inside the outer assembly. I found excessive clearance between the inside unit and the the outer assembly. On a Ruckstell it should be around .006" On mine it is about .050" Perhaps there was a fibre thrust washer on the bell housing end that is no longer there. So I planned on making a spacer either fibre or bronze after cleaning up the rough surfaces on a lathe. The shim must be on the bell housing end because distance of the inner carrier on the ball bearing end is set by a thick steel thrust washer and is critical for the gears to engage properly. My shim will run against the bronze thrust flange surface of the bell housing and the outer surface of the diff carrier. The pictures should help explain what I'm talking about.

Here are some photos of the clutch. Notice how it is an assembled piece that is captured inside the driver's side outer housing, the piece that holds the ball bearing. The small gear is pressed on and the brass shifting ring is held in place with split washers and a compression ring. Kinda different than a Ruckstell, but works the same.