So, I just bought a MacBook 7.1 (Mid 2010) from what by all appearances is a reputable eBay seller of used Macs. One of those companies that buys and sells used Apple stuff. I just noticed that the serial number on the bottom case is different from the SN that is shown in System Profile. They are very similar, in fact I didn't even notice it at first because they have the same first four characters and the same last three characters. Only the middle four do not match. I am not well versed in the used Mac landscape or in the used anything landscape for that matter. My only other experience with used Macs was a different one from eBay a few years ago from a similar seller that I ended-up returning because of a DOA firewire port. Is this within the realm of normal? Or did I unknowingly buy a 6 year old, $200 MacBook from a chop shop?