So for the past week that I've had the Quad, I've had no luck finding the S/N anywhere including the Apple website. The only other thing I can say is that it may be a prototype, the S/N indicates that the Quad was made in the US in August of 05. The sticker on the bottom that includes the EMC and Model numbers is missing. There was sticker residue on the bottom that could have been the DVT sticker but there is no way to tell. Besides from that, everything seems completely normal, a blue logic board, and all. The DVD drive was manufactured in June of 05, once I get the power cord and graphics card I should be able to determine more. The S/N is G85344FCU7N