You are right, Porkpal, the breeder was Bizot, 1868. But David Austin sells it and is generally really good at giving advice, so it might be worth a shot.
Since (unless I am wrong, which I may well be) Bizot no longer exists, then asking a reliable seller might be an option. Up to you, Applevalle.
I should perhaps add that the DA website says of Zephirine Drouhin that 'Controlling disease can be a problem'. But they do have a wonderful, very old rose garden at Albrighton and may be able to give you some advice on how best to try to rescue your wonderful rose. They have certainly given me great advice on several occasions, and don't charge for it - nothing ventured...
