If the date is unreadable, it can also be written on the body under the pickguard or cavity form the pickups.
January 1965 Fender was acquired by CBS Corporation.
Fender's production methods from the early fifties had the effect the numbers may not be consecutive.
Also overlap of serial numbers and dates come with regularity.
The table below shows the serial numbers as they were used from 1965 to 1976.
Again, there are a several serial numbers that overlap.
Most specifications for a given Fender instrument model change little (if at all) throughout the lifetime of the model.