Well, I have missed this piece...and its seriously interesting
a superb piece...
however the "private" designs/custom stamps/private issues I don't think are listed at least for now
the only way to get listed in a stamp catalog in this case is to speak directly with the publisher... I have a particular variety of an italian stamp (very few pieces known) and the only way to see it listed in one of the main catalogs is happened with the direct contact of the publisher ...
Or another solution is to have a specific catalog for crypto-themed stamps...a pdf example was posted few weeks ago.
Thanks Bitbollo.....I made two of them...one I auctioned and the other I kept for my collection of course
Its loaded with both BTC and BTC cash and all other forked coins that came as it was loaded before Ausust 1st 2017.
So not only are they unique to being the very first but also to having all these forked BTC coins in them as well.
I will some day try and reach out to the catalogues and see what happens....not holding my breath though.