It seems there was also a Villa Archinto at Monza, a view of which is presented in a painting by Giuseppe Canella, something which, in my view, strengthens the suggestion that this rose was raised by Casoretti.
The Villa is stiil there! It was built, on a pre-existing villa, for Count Archinto by Luigi Canonica between 1829 and 1840. Canonica disegned also the large park adjoining the park of Villa Reale and the river Lambro. http://www.lombardiabeniculturali.it/architetture/schede/3o290-00013/