It's a transitional style, and I think its from c. 1976ish, when styles are shifting from the blocky heels and round toes of the early 70s to the spike heels and almond toes of the late 70s. I'm not quite sure when or if the Delman label changed, but that label was certainly around in the 60s. The company closed in 1988.
Agree it's middy late 60s and I think this is Delman for Rayne. I could swear I've seen the advert for it somewhere too with Edward Rayne on it himself - it was part of a series he appeared in.