Thanks for the responses.
The BNA Topics article (reprinted from Scott Stamp Monthly) as linked above (pages 10 and 11) pretty much explains it.
I subsequently found an article a few years earlier that gives a thumbnail sketch of what happened and is quoted below (for the benefit of those who may not want to download the entire newsletter referenced earlier):
It is interesting that there were a number of varieties of this "stamp" produced, some of which seem to go for pretty hefty sums on auction sites such as
eBay, etc.
Posted 05/01/2013 6:46 pm
