Oleg Cassini definitely raced at Monticello and Pompano, I am not sure about Freehold. He was a horseman in his younger days, and had he not commenced driving horses when he was about 70, he might have been competitive, certainly with the amateurs we see today.
I was with him at Pompano when he came out of the pocket prematurely, interfered with another, and was DQ’d. Later, I told him he should have put his right turn signal on before moving. Fortunately, he had a sense of humor.