@BibiFricotin: if you are interested in crypto stamps you really should dig a little bit into @krogothmanhattan's work in this area like here https://bitcointalk.org/index.php?topic=5412935.0 You are pretty much at the source when it comes to crypto stamps (no BS) and maybe there are still some Cypher Stamps left http://www.crypto-stamps.com/cypher.html => totally worth it; wouldn't wanna miss them in my collection!