With production growing rapidly by 1980, the serial numbers had gotten about two to three years ahead. Bolt-neck guitars are less precise for the usual reasons.
For example, a bass guitar that is documented to have been purchased (not necessarily made) in 1980, bore the serial number #82595. The serial number is stamped on a neck plate, and like every other company, when the guitar was being finished, someone grabbed a plate out of the box and put it on in no particular, precise or documented order.
Japanese-built Takamine Pro Series guitars can be reliably dated from the eight-digit serial numbers typically found at the neck block inside the instruments.
The following number determines the model: 5 or EG for the EG models, then the sequential number for that particular model.
The year of manufacture is determined the same way for the Swamp Ash Special.
In these eight-digit numbers, the first two digits signify the number of years since Takamine’s establishment in 1962.
The following two digits denote the month, and the remaining four digits denote the instrument’s sequential number of manufacture among all the instruments made during the month indicated.
Date-coded serial numbers are typically found stamped on the back or top of the headstock, and "Made in USA" is stamped next to the number starting in June 1967. The next digit = last digit of the year (1966 to 1972: 6,7,8,9,0,1,2).