Here's a pair of forgotten Milky Way candy ads from the 60's, back when Mars, Inc. actually promoted themselves.
The first spot is animated, with the inestimable Paul Frees as the voice of the candy bar. The second is a live-action piece with silent movie legend Buster Keaton.
A check of Wikipedia claims that the defunct Forever Yours bar was a dark chocolate version of Milky Way that had been around for years. Not that I could recall. Forever Yours actually was a short-lived brand and was revived under the Milky Way label twice in later years (Milky Way Dark & Milky Way Midnight), neither of which got over all that well, either.