Just like vintage cards and classic baseball cards, guitars can be very, very old.
Gibson, since being founded in 1902, has produced a rich history of instruments, with numerous models, special editions, and re-issues.
Because there are dozens of subsidiaries associated with Gibson, there are specific tips on locating the serial numbers for Gibson guitars and other instruments, specifically.
The headstock, inside of the guitar, and the back of the neck are the most common locations of serial numbers.
If the owner still has trouble locating the serial number, check any receipt documentation that came with the guitar.
If documentation is not available, contact the seller of the instrument as they may have that information on record.
Cleaning or the effect of time often results in the serial number wiping away.
Use a strong source of light to reflect light off the body.
Even when rubbed off, serial numbers leave an imprint on the lacquer seen with the reflection of the light.
There is no guarantee, however, especially if it has a new layer of lacquer applied.
Sellers found on e Bay may have offers for reference materials.