shooters, I just picked up a Ithaca 37 w/ corncob 16ga. . like so many 16ga's I like to check manufacture year and this seems to be either 1946 or 1956 -not sure but the serial number is 464814-4 . what is throwing me is the -4 number as I see it nowhere in the books ??? straight Numbers but none with a -minus number at the end? Any suggestions or guesses? Thanks-Steve