Although I've never seen a Combo fitted with a Kaufmann outside of the Smith book on Rickenbackers, I was intrigued by the prospect.
So, I bought a new Kaufmann and gave it a shot. Here's what I discovered: The guitar in the Smith book probably had a non-functional vibrato, as the geometry of the Kaufmann is such that without about 6 degrees of negative set on the neck, the action would have been too high to be playable. The guitar in the Smith book looks like a standard Combo 400, though. Solution? Make a clamp to lower the strings between the vibrato and the bridge. It's hidden under the bridge cover, which has been cut away to clear the tailpiece.
So, it looks cool, plays fine, and has a non-functional Kaufmann. The arm is a long straight Kaufmann arm, which has been given a bend to fit the guitar's playing position.
Sorry to disappoint. Hey, I'm not Superman!