"if these stamps are genuine" - the better stamps won't all be genuine or sound.
Mr. Ryle has been a great story teller on
ebay for many years. Recently he has begun to selectively use this "dead dealer card" gambit to enhance his listings. Like the other elements of his MO (e.g. a few older PF certs in each lot that are clean or almost clean, some recent PF or PSE certs for some lower value items, etc.), it all goes together to help him give a potential buyer some false feeling of security and therefore increase the probability of a sale and the selling price.