An extremely odd "twin," as pointed out by contributor Dan Kurdilla, from Wyndmore, PA, is Lion Library LL2 and Tuxedo 124. The Lion book appeared in 1954, the Tuxedo book in 1962. I am unaware of any link between the two publishers. Dan points out that Martin Goodman, the man behind Lion Books, was also heavily into publishing men's magazines, and may have had something to do with adult-oriented books such as this, though that has not been documented (as far as I can find).

Dan contributed the Tuxedo scan.  Fred Meyerriecks contributed the Lion scan.