In another month or two I'm going to be acquiring a compensating euph, partly (though not solely) for use as a tenor tuba. I have a Schilke 60 that I used some years ago for bass trombone and will probably make use of that in the euph. But I wonder if anyone has any experience with the Rath contra bass mouthpieces in this regard. In particular, the CB0 appears to be very close in size to what I use as a tuba mouthpiece (at least in terms of rim diameter and throat).
So ... Does anyone have any experience with these in a euphonium? Do they have the standard bass trombone shank a la the Schilke?