The Wheel of Passion by Charles Verne aka Orrie Hitt and Joe Weiss (Key Publishing, 1957)
Orrie Hitt, with (we believe) Joe Weiss or someone else, used the pen name Charles Verse twice: Mr. Hot Rod and The Wheel of Passion, the pen Roger Normandie four times, and possibly Fred Martin with Hired Lover. The Key Publications books all came out in 1957 and were in hardback. The telltale signs are alternating chapters with different writing styles, hardcore S/M spanking scenes, and sections in italics. The language is a tad more racy than that in the paperbacks.
The Wheel of Passion covers territory that Hitt would later re-vise in Carnival Girl, Carnival Honey, and Carnival Sin. Yes, the narrative is set around a carney, focusing on Bunny, a terribly gorgeous redhead with a 38-inch bust, whose father owns a carney business and has kept her shielded from that life, sending her to private school and raising her in a upper-middle-class community. Her father has just run away and married one of the carney dancers, a woman half his age, so is incommunicado; the carney manager comes looking for him, frantic because several routes are in dire financial need. Bunny decides she needs to jump in and help the family business.
So Bunny jumps in, she becomes a dancer, she has lesbian encounters, she sleeps with the manager, etc.
An okay book. Mr. Rot Rod was the better Charles Verne.