I'll make a suggestion that "Agnes Saffron" could be a cross or seedling of 'Mme de Tartas' because it appears from the photos to have a squarish receptacle not dissimilar to the Cochets. Neither parent of Maman Cochet seems to have this feature, but both parents ('Mme Lombard' and 'Marie van Houtte') are seedlings of 'Mme de Tartas', so I'm just guessing that it is perhaps a characteristic passed on through her.
Which seedling of 'Mme de Tartas' could it be? I don't know; when I look up the 1st generation descendants, the list seems incomplete because neither Mme Lombard or Marie van Houtte appears and I'm sure there should be others there too.