I have Disney mini-one sheets going back to the '87 release of Cinderella (glass slipper version). For other studios you didn't really see mini's until the past 5 years or so.
The one exception is the Topps (the baseball card company) series, which consisted of folded versions of some of the bigger hits of the late 70's (Jaws, Smokey & the Bandit, etc.).
Anything listed as a mini-one sheet, other than those mentioned above, is more likely a reprint than not...