hey randy,
here are a couple pics of my 1956 commander. it has metal gunnels. in 1955 and 1956 both, you could choose oak or aluminum for the splash rails and the gunnels. although the catalog says aluminum was standard and oak an option for ’56.
the serial number is visible on the starboard side where the back of the bow cover meets the side of the boat and down a couple of inches. mine is A7219
also here is a pic of my corner bracket. no mention of Larson.
hope this helps!
scott