That's interesting. There was a Holton/Couesnon connection! Please tell us more. I have a Couesnon alto that i like very much. There was also a Couesnon/Yamaha connection that i can discuss, but it's off topic here.
alto: Super 20, B&S 2001, JK sx90r-NS> Aizen tenor: B&S Medusa, Selmer Mk VI> Gottsu soprano: Yanag. S-991> Super Session E bari: Yanagisawa B901> Berg rubber