I played that horn extensively last week. It's an actual CB/G-50 valve section placed on a York - Mr. Fedderly told me he believes Bob Rusk replaced the valve section from the prototype with this one, which makes some sense. The leadpipe is not a Getzen leadpipe - and it sits away from the bell (which I liked). The configuration of the fifth valve trigger is unique as well. The York sections are quite thin compared to modern standards, but make for a very nice horn to play. It's a very light horn. The 5th valve is a half-step, not a whole-step (but that can be changed easily enough). Pitch seemed good to me, what you'd expect from a CB-50.
The horn plays fabulously. It plays like a CB-50, but plays more like one of the "early" horns in that line, which I prefer. I'm debating buying it for myself (even though I own a earlier CB-50) but I'm sure someone will snap it up PDQ.