The main Dutch source was Henry Surie's diary - hardly an official document! However, Pierre Richier was his maternal great grandfather.
Henry's father Johann had married, in London, Elisabeth Wilhelmina Sievers, daughter of Petronella Richier and therefore Pierre's grand daughter.
From Henry Surie (Translated from Dutch)
"My mother's grandfather was a Frenchman by birth [this was not true. he was born in the Hague, of French ancestry via his grandfather Charles Richier, born in Celle, Germany].
Since he was the Baron Richier, and belonged to the French high nobility, he obtained a post of trust at the Holland Court, as private secretary of the Prince of Orange. My maternal grandfather fled from Scheveningen to England with Prince William V. "
and
"My father requested from the Dutch Government a pension for the daughter of the late Secretary of Prince William V. As the daughter of Baron Richier, and because of her late spouse, she (Petronella) also obtained a pension from the British government ,"
She was certainly recorded in 1836 in Amsterdam "of independent means"
We have been unable to confirm any Barony, and the diary is certainly unreliable in other places!
Henry says that the family property in France had been given to "relatives of Guichot, the minister of home affairs" and his father spent all his money trying to retrieve it.