Crypto Stamp version 1.0 OnChain has the attribute with different possible status Shop Status: Initial/Sold/ShippingSubmitted/ShippingConfirned. Initial means still at Onchain Shop available. With status sold you can order via smart contract the physical counterpart. This special physical stamp does not have the private keys/seed because you already have the NFT. Instead there was a special text: this crypto stamp was bought and delivered after purchase via smart contract
Oh. So if you have bought the stamps onchain, paid it with Ether, you would have got the NFT to the wallet, from which you have paid them? Hopefully nobody made the mistake and connected the NFT stamps to his wallet with heaps of Ether...