Scooping rotors on a Reynolds bass trombone

[martyneilan]

Years ago I remember reading about someone having the rotors on a Reynolds bass trombone scooped out and the horn was transformed.
Is that person on this board, or does anyone have any information about that horn or the repairman who did it?
I have owned both single and double valve Reynolds basses in the past. As much as I loved the sound of the “tangerine" the double rotor had an inordinate amount of resistance when both rotors were engaged even when perfectly aligned.