Although the references invariably give 'Julien Potin' x 'Sensation' as the parentage, the 1936 US patent gives a more subtle pedigree.

"Parentage:- Both parents were unnamed seedlings with seed ancestor Julien Potin and pollen ancestor Sensation."

I read that as ('Julien Potin' x 'Sensation') x ('Julien Potin' x 'Sensation').

The usual parentages given for the other four Aicardi roses with US patents (Eternal Youth, Rome Glory, Saturnia and Principessa delle Rose) are the same as given in their patents, so I see no reason to doubt the patent parentage for 'Signora'.

In Southeast England (mild and cool, zone 8) this year’s first flush of flowers had a very strong and complex scent half-way between fruity and perfume/eau de cologne. Tea wasn’t evident in it.

I think it fair to remember the name of Signora (Mrs) Piero Puricelli, her name was Antonietta Tosi.
http://notes9.senato.it/web/senregno.nsf/ed09445904d7899dc1257114003829b4/c8d9d90adee649064125646f005eca80?OpenDocument

You may be interested to know that Piero Puricelli was a Milanese carnation lover who first visited Acardi at Villa Minerva in early 1925. His letter of thanks to Aicardi is dated 2/5/25.