Once we got home, I rushed to open the computer and dug out Hubin's crime fiction bibliography (on CD) and checked who'd written the Hank Janson book Lust for Vengeance of which I write down below. It seems that the writer behind the pseudonym is not known. Maybe the info is found in a later edition of Hubin's bibliography, but I can't check that. Nevertheless, the book is from 1965.
I'm now reading another Janson title, Deadly Horse-Race (1967). That one is by Harry Hobson and it involves Red China's attempt to crash USA by dumping very cheap heroin in the market. The mob and everyone else goes crazy and only Hank Janson can save the day. Lust for Vengeance was a better book.
Note also that the British paperbacker Angus Wells died during the Easter. There's not much translated from him - only two possible westerns as by Charles R. Pike, but since that was a house name, I don't really know if it is him.