Most notably, production dates have been penciled or stamped on the butt end of the heel of the neck of most guitars and basses, although there were periods when this was not consistently done (1973 to 1981, for example) or simply omitted.
instrument production history, production dates have been applied to various components.
Given the modular nature of Fender's production techniques, an individual neck may have been produced in a given year, placed in the manufacturing warehouse and remained in stock for a period of time, and then subsequently paired with a body to create a complete guitar in the following year.
Therefore, while helpful in determining a of production dates, a neck date is obviously not a precisely definitive reference.
Most specifications for a given Fender instrument model change little (if at all) throughout the lifetime of the model.
Your last chance to own a vintage Fender Stratocaster is with the guitars of the late 1970's.
You spot a '79 in a local shop, or online, but how can you be certain it is a '79?
Some dealers simply go by the serial number, which you will discover can be far from accurate.
Some might go by the pot codes, but those could have been stock a year or more old by the time they were put into the newly finished guitar.
Unlike the auto industry which has specific model years for their products, most specifications for a given Fender instrument model, change little if any, through the lifetime of the model.
While there have been periods where dramatic changes have occurred, for example: the transition periods between Leo's Fender and the CBS years, as well as the transition between CBS' Fender and the current ownership, generally speaking, most models are feature specific and do not change from year to year..
Neck-dating can be useful in determining the was produced, rather than the complete instrument.
Given the modular nature of Fender production techniques, an individual neck may have been produced in a given year, then stored for a period of time before being paired with a body to create a complete guitar, perhaps, for example, in the following year.
Or perhaps the guitar was even assembled by various parts picked up over the years and is being passed off as "All original".