I also have the Galen books he has. Not much decoding info about 64 California car. In 65 they started to standardize the codes and fender tags a bit. You car is very simple so there only 4 option codes to decode. You already know it is a 273-2/4 speed built in California. H is the heater and P are mirrors. The SO on the bottom is the scheduled production date (not the actual date) and the Number is the shipping order number. The rest is paint codes.
