There are a few elements that points to Attilio Ragionieri as breeder of this rose. 1) Ferdinando Scarlatti and Attilio Ragionieri were working in the same period in Florence and were "acquainted" and it would be right for him to baptize a unnamed rose with the name of his dead friend; 2) this rose is, strangerly enough for the period, a HP; 3) in Costa azzurra agricola floreale 1930 page 314 Attilio Ragionieri wrote "Il Dr. A. Ragionieri ha fecondato a Castello (Firenze), i fiori di R. gigantea col polline di alcune delle più belle varietà del commercio (1). … Dall’incrocio con la var. Prince Camille de Rohen, ottenne una pianta vigorosa, che ha cominciato a fiorire abbastanza presto: i suoi fiori ben doppi, molto grandi, a lunghissimi petali, hanno il colore di quelli della varietà Ulrich Brunner e sono molto odorosi" (translation Attilio Ragionieri in Castello (Florence) bred flowers of R. gigantea with pollen of some well known varieties (ref 1). The cross with Prince Camille de Rohan gave a vigorous plant, that started rather early to bloom: the flowers are well double, very large with very long petals, the colour is similar to Ulrich Brunner and are very odorous); 4) the reference 1 quotes a 1926 article by Ragionieri (I did not find it jet).; 5) Prince Camille de Rohan is a HP with "the right colour" ... Not one prove but certainly many many hints ...