My suspicion is that 1976 is the year of construction, based on the number on the board. You have an excellent example of a rounded pin gun. The shape is very similar to some of Billy Casters’ boards of the period. Hang on to it.
I had a Channin that I bought in Florida in 1975 that is very similar to that board sans the 2 outer stringers. I think it was shaped by Duane Brown or Steve Moret.
I’ve been told that around that time Bahne had stopped making surfboards in order to focus on their growing skateboard business and Channin had hired their whole crew. So most likely it was glassed by Wayne Hoshisaki. Wayne had it down. His resin tints and and cut lap clears where flawless- no score marks into the foam.
Channin was one of the last cut lap hold outs when everyone else was moving to free laps. Kept using volan cloth and that darker Dion resin that Tony said was stronger than the clearer Reichold everybody else was switching to.