Although Vixen existed, I'm not sure Mark Tryon did. It was a pseudonym. At least the Library of Congress thinks it was. On the other hand they list no more books by the author and I have three in my hand right now, so I dunno. If you can't trust the Library of Congress, who CAN you trust?
Mark Tryon also wrote Stage-Struck and Take It Off..but unfortunately, everyone did...the dust jacket, that is. I can't find one. Someone who has it stuffed back behind a fat best-seller from the 1950s will send one along, I am sure.
Mark wrote seamy and steamy.
Three years after the Modern edition, the Sinning Lens were cleaned up again and came out under the Berkeley imprint. Same book and the same broad who "had a touch of exhibitionism in her make-up" according to the book jacket.
Mark liked to pen books about women who might not necessarily like men. For example The Twisted Loves of Nym O'Sullivan. He also wrote Of G-Strings and Strippers for Beacon 1954, Sweeter than Life, Stagestruck and The Fire That Burns (AGAIN with the camera...Mark was in a rut.)