I was unsure where to place the 1985 Peter Beales reference. Two choices: "Dembrowski (in commerce as)" Light pink. Dembrowski (portland, Vibert, 1849) Crimson, violet shading. While it was in commerce in 1985, his description of reddish-purple is closer to the original colour, than is light pink.
I would be surprised if he had anything else than the rose at Mottisfont. My conjecture is that he took the description for the catalogue from literature.