Teisco serial number dating
That would date these guitars to 1963-1964, I guess.
In these examples an F62 would mean it was part of the mass of guitars they made in the Fall of 1962, or the S66 would stand for Summer of 1966.Then if you are very lucky you will also find a letter followed by a two-digit number.For example you might find something like F62 or S66.I think over the years they made guitars with over 50 different sub-brand names and sold them through all kinds of outlets.
Get yourself a flashlight and a mirror and examine everywhere on the inside of the guitar.
The photos are either internet findings or photos that have been sent to me.