I've just noticed that the date you give for the Saverne Silver Medal award for Rosalba is 1935. That can't be right since the 1934 article I quoted already refers to it.
No, but since the article in Il Giardino Fiorito is dated, as I pointed out, November 1934, and reports the winning of the silver medal at Saverne, it can't be true that the medal was won in 1935.
The september-october 1934 issue of Les Amis des Roses (page 121) lists Rosalba among the “Nouveautés 1934”. In the description of this rose it reports “.. Médaille d’argent Saverne”. I think that this is enough to date the award.
The parentage of 'Rosalba' is the same as 'Jacqueline Mennrath' according to Il Giardino Fiorito Nov. 1934 p. 187, that is: Souv. de Claudius Pernet x Willowmere.