I found out there's an archive of every issue of the magazine, but I'll stick to the issues I have.
All are from #66, April 1966
Avis Rent-a-Car had the campaign “We're number two and still trying harder”
We Are Second Union Christmas interview with Me.... - http://wearesecondunion.com/2017/12/12/interview-rick-goldschmidt-historian-biographer-rankin-bass-productions/#.WjBi0QC0dGi.facebook
15 minutes ago