The year of manufacture is determined the same way for the EG models.Like the CE models the serial number is located on the neck plate on the back of the guitar.
The model numbers can be somewhat confusing because model numbers such as 1987 or 1959 can be mistakenly interpreted as the production year of the amplifier.
Amplifiers from this era must be dated within this time span based on their features, or component manufacturers and codes, including speakers, potentiometers and transformers.
From 1964-1968, the serial was ink-stamped onto a silver foil sticker that is found in the same place.
The following is a key for decoding the serial number, but keep in mind that the numbers are approximate.
After the year prefix, these models us a code digit of "9", indicating a set-neck model bass.