I've been watching this thread for a few days now, waiting for the little grey cells to pull something out of the deep recesses. That trade magazine ad did the trick.
The background color of the can the Vanilla shake came in was indeed BLUE. I also remember reading that the can said "A melloream product" on it, whatever that meant. Also of interest is that the headquarters of Borden was still at 350 Madison Avenue in Manhattan at that time.
At the time, Borden's also made a canned egg nog. I always thought the shakes were an offshoot of the egg nog line of business. I never heard why they were dropped from the market place.
The Borden's canned egg nog LOB is still around, and is owned today by J. M. Smucker: http://www.bordeneggnog.com/
Now if only someone could convince Smucker to make those canned shakes again.