I have grown both 'Pergolèse' and 'Rose de Rescht', both on their own roots, for several decades. While the blossoms are quite similar--not lookalikes, but quite similar--and both bloom gratifyingly throughout the year, 'Pergolèse' sends out suckers and runners with some frequency, and 'Rose de Rescht' never does, absolutely never (I wish it would!). (Before anyone says, "But my 'Rose de Rescht' sends out suckers abundantly!", be aware that it appears that many who have what they think is 'Rose de Rescht' actually have the suckering 'Rose du Roi'.) Also, 'Pergolèse' is taller, branches less, and has a looser, more open, habit than the bushy 'Rose de Rescht'.

This cannot be the same rose as is shown in the other photos for Duchess d' Angouleme. Both flower shape and leaflets are substantially different.

Available from - Lens Rose
https://lens-roses.com/fr_FR/shop/belle-de-terre-franche-15065#:~:text=poudré%20au%20centre.-,Arbuste%20buissonnant%20et%20sain.

The 1811 in the Thory/Redouté quote refers to the publication of Lelieur's "traité, très estimé, sur la culture du Rosier," not to the development of this rose. According to the text, the rose was bred "several years ago" ("il y a quelques années"), before the publication of this section of their book Les Roses, which, yes, could be 1811, but probably wasn't, as had it been some locution such as "that same year" (1811) would probably have been used rather than "several years ago."