I have four sheets I tape together to make one big one.  Mine is hanging in the garage and refer to it all the time. There are differences between the 1955 and 1956 schematics with the addition of a ballast resistor because the '56 was the first year to change to 12-volts. Positive or negative grounds meant no device changes except for the heater motor. If retrofitting a '55 to 12-volts, a gauge CVR must be installed.