This is purely a wild coincidence, but I've found out there's an article about Orrie Hitt in today's edition of the Port Jervis, New York newspaper (Hitt's hometown). You can read it here.
According to the article, he died in 1975, not 1967, as I stated in the previous post. But I think his last novel was published in 1967. That must have been what I was thinking of.
Hammett: The Too Big Book of the Op
3 hours ago