You're right, and that gets more confusing. Buck used left over drilled handles, and converted them to more or less pins. It's really hard to pinpoint a year made by the pins. Markings on the blade are more reliable, and accurate.
Some say the 4 pin started in 82, but that is probably wrong. Mine is a 3 pin, and I know it was built in 81.
Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the outcome of the vote.