Definitely a garter grip. Oh, gawd, the memories. Actually, you can still find them if you go to the right "places."
In response to bigcypresshunter, yes, they were cumbersome some 45 years ago, but that's what we had to deal with. Back 50 years ago, I remember my grandmother wearing a full corset, which "embraced" her from 'here-to-yonder,' which was reserved for Sundays and special days, of course. All other days she dressed as I do now: sloppy, but comfy.