Mod Edit: I've copied this post in here from a regular id request thread.
Sexy Girl no 17
Undated, but late 1960s. The pics from ifr2lax are also from that mag, in fact I very much suspect that they are a scan I once made myself.
Regarding the id-reliability of the mag, I'd say: average for the time. Several known models of the time were given to us under their usual name (Shirley Linden, Maria Frost, Marie Estelle, etc), but e.g. the title girl (Cheryl Peters) was not: she was introduced as Nadine Miller.