unfortunately, I have just received this from Gap-Charence: "Suite à votre demande qui m’est parvenu par le Conservatoire Botanique National Alpin concernant la rose « Alix Reusel » nous ne pouvons donner suite, cette variété ayant disparu de notre collection."
Agree. If every private gardener took it upon themselves to safeguard just one rare old rose, with provenance, and which does well in your area, the losses will be greatly minimised in the future. The rose itself will give you your reward.