So is the 11B on the trim tag a Fisher date and the official production date a GM date?
Were the bodies assemble at a Fisher plant and shipped to Van Nuys or was all that done at the same plant?
Edit -
Fisher Body Division Plant, Van Nuys, Los Angeles, Opened 1947 with Plant Code #L, attached to Chevrolet Plant. Changed to GMAD in 1968 and was merged into the Assembly Plant.
So Fisher Body and GM Van Nuys were right next to each other. Odd that it would take a week for a car to travel that far.