Instead, the best approach to dating a Fender is to combine indicators from the design of the instrument, the dates found on the neck and body, along with the serial number. This also means that various parts used on a particular guitar may have come from different points in time, so no single number can absolutely define when the instrument was built.
Features like bolt-on necks and pickups wired into the pickguard all helped the Fender factory churn out guitar after guitar, day after day. His guitars were built en masse by an entire factory, not a single luthier toiling over one instrument at a time. Like Henry Ford, part of Leo Fender's genius was in optimizing the company's production efficiency. The most important thing to keep in mind when dating a Fender is the highly modular nature of the designs.
