box.
Not really adding much, but she was also on the cover of Tiger, 1973-Spring.
I don't know whether the name Nancy Robinson, shown on the cover, pertains to the cover model or not.
While I'm about it, here's a slightly larger version of the mystery box cover from All Man, 1973-02.
edit: Tiger seems to have been part of the Modern Man stable, and both often seem to have named the cover model in something like the above fashion--though sometimes more explicitly, e.g. with an arrow. So maybe this should be(come) a mystery-unfolded as Nancy Robinson?