Hofner's sold through their UK distributor Selmer of London during the 60's had serial numbers stamped on the back of the headstock. Those serial numbers are very traceable.
For 60's made Hofner's the best way to determine the year of manufacture is both visually looking for specific features and to date the volume pots. If you don't know how to read the pot codes PM me and i'll explain it to you.
Originally Posted by Mr. Mig
Even the new hofner's don't have them on the instrument. They are usually on the original paperwork that you get when you buy a new one.
Sorry, but that's incorrect. Since the late 1990's Hofner has been placing the serial number on a label that's glued to the instrument inside the body cavity right underneath the control panel. Remove the control and you'll see it right there.