If I'm reading things correctly over the Steve Hoffman Forum, the young lady on the cover of Chris Montez' TIME AFTER TIME is Erin Gray, actress and model. If you're a member there, it's in this thread:
http://www.stevehoffman.tv/forums/showthread.php?t=103085
And if one is to believe Erin Gray's biography at Wikipedia, she was born in 1950, and would have been 16 at the time of the Chris Montez cover photo.
For those who aren't familiar with Erin Gray, she was first a model (apparently the first L'Oreal "I'm worth it" lady) and later went into acting, playing Col. Wilma Deering of the BUCK ROGERS IN THE 25th CENTURY TV show in the late '70s, and in the '80s was in the sitcom SILVER SPOONS.
I just find this fact fascinating, yet other than the Steve Hoffman mention, I can't find any other confirmation of the fact. But since he seems to know her personally, I guess it's likely true!
Harry