A number of the references for the gallica 'Velours Pourpre' list the Dutch/Netherlands/low countries as the source of this rose. Quite likely the specific source would be Cornelis Stegerhoek of Holland who bred a gallica by this name. That information is listed in Hardy's 1837 Catalogue on page 54.
According to François Joyaux ("La Rose de France") the plant in L'Haÿ is 'Velours pourpre'. The label 'Velours noir' at L'Haÿ is incorrect. Neither of the two gallicas were there in Gravereaux's time. We again will separate the two roses, based on the information from early literature.