Don't know if it's what you're looking for or not, but Phil D'Rey published a routine for a "silent" vent in one of the Ireland Yearbooks. I don't remember the year offhand (and thanks to hurricane Katrina I can't check), but I remember that the cover was pink with blue print. I'm relatively certain it was the 1953 issue. For what it's worth, it was a pretty decent routine, as was most of D'Rey's other material (his chapeaugraphy routine is apparently unknown to all but the most tenacious of researchers but I feel it's one of the best).
New Orleans, LA