Carl Thompson started building instruments in 1974.

Determining date of manufacture for Carl Thompson Guitars / CT Basses

You can tell the year and date of manufacture by a serial number on the back of the headstock in MM DD YY format.” [Source: -Aaron, CT Basses email 29/4/2008]

1979 Carl Thompson Bass from ebay:1979 Carl Thompson bass

Serial number examples courtesy of Aaron, Carl Thompson Guitars:

Carl Thompson Guitars serial number Carl Thompson Guitars serial number Carl Thompson Guitars serial number