Take a look- if the serial number is 6 digits or less then your guitar is older than 1976. If there's no serial number there, look on the back of the neck at the very top just above and between the tuners. It should be on the inside of the bass side F hole on the paper label. The serial number is one of the first places to start for how to date a Gibson ES-335 guitar. If you're looking for help with how old is my Gibson Les Paul guitar, check out How to date Gibson Les Paul guitars. Click the red Contact Me button in the lower right corner of your screen to send me information about your guitar. Need help? I'd be happy to take a look at your guitar. This checklist will also help with how to date Gibson ES-345 guitars and how to date Gibson ES-355 guitars. This is my check list on how to date a Gibson ES-335 guitar. Knowing how to date a Gibson ES-335 isn't as easy as checking the serial number! Gibson serial numbers are only one part of the puzzle that is Gibson guitar dating. Finding out how old your Gibson ES-335 is should be the first step in evaluating a vintage Gibson guitar.