Dating vintage fender pots
Here is the S first introduced as a prefix to the serial numbers. The E stands for the decade of the eighties, and was introduced in 1979.
Fender moved the serial number to the back in 1996. If you can not find a serial number (unreadable, worn of), you can approximate the age of a semi/electric guitar on the basis of the potentiometers.(Stratocaster) Between 19 there were periods that this is not consistently done.