About few years back I bought a mixed bag of worldwide stamps from eBay. This was a real ‘look what the dog ate for breakfast’ mix containing all sorts of odds and ends. But there was also something a bit more special items: two misperforated 1971 8 cent Eisenhower booklet stamps (Michel#1032D, Scott#1395a).
The below photo displays a regular stamp on the left, and misperforated specimen on the right:
This stamp was issued in sheet, coil, and booklet formats, all of which seem to contain more or less common perforation errors. Misperforated booklet stamps as mine sell for US$10 or so on eBay.
You might also be interested of related posts about Stamps and postal history of USA.