Looking on KEH's site a short time back for a couple more A12 backs, I noticed that the remark "matching numbers" appears frequently as part of the product description for the A12s. Anybody have any idea why? Is this a variant/mutation of "Fanboy-itis," wherein the serial number of the A12 casing must match that of the insert? (lol) Do "correct" serial numbers influence market value, and if so why? It's not that I give a s**t (all six of my current A12s do, however); I am just curious as to why KEH - and other sellers, I assume - make mention of the fact.