I'm only speculating here but I have noticed on these posts a pattern. While it is true Fender has a messed up numbering system, it seems that for some of the numbers, there is a pattern. My F55-12 has a serial number of F 7933161. I received it from my mom for, I think, christmas of 79 or my birthday in 1980. I have a picture of me playing it in the fall of 80, possibly the early winter of 80. As I read some of the posts here, there are serial numbers beginning with 72, 78, etc, and my begins with a 79. It is very plausible to believe that on some of these numbers, they reflect the manufacture date. I believe mine is a 79 because my mom bought it brand new and I received it shortly thereafter. I shaved the bridge down a bit several decades ago and learned how to pick it in the style of Chet Atkins. I love this guitar. I hope I have been of some help or at least given you some ideas to ponder. But I don't know for sure.