Delrin, Polyamide, Polyacette, Hostaform, Polystyrol, Lucite, Acrylic, Perspex and Bakelite were all part of a new medium of 1960's & 70's plastic watchmaking (the first all plastic watch-->link). With flexible materials came flexible designs and like animated characters in a cartoon, the creators were able to push limits of the physical world.
Some vintage polymer highlights...
Above; 1970's Record by Longines Automatic Sideview Bracelet.
70's Buler Volcano
1971 Pierre Cardin
70's Mount Royal Curvex
60's Lucerne CuffbusterAnd just to point out, these are all mechanical (manual wind-up and automatic) watches. The Swatch revolution was still 10-15 years away.