The answer can be found in "Spanish Treasure" by Terry Wieland. According to this guide, the gun #524948 was produced between 1978 - 1983. Your gun will have a date code stamped on the barrel flats. To determine the exact year of manufacture here is a list of the codes: 1978 - X1, 1979 - Y1, 1980 - Z1, 1981 - A2, 1982 - B2, 1983 - C2
with the serial number that you provided,your Winchester model 12 shotgun was produced in the year 1935.
With the serial number that you provided,your Winchester model 1912 pump action shotgun was produced in the year 1950.
With the serial number that you provided,your Winchester model 12 pump action shotgun was produced in the year 1928.
With the serial number that you have provided,your Winchester model 12 pump action shotgun was produced in the year 1955.
With the serial number that you provided,your Winchester model 12 pump action shotgun was produced in 1942.It was one of 50,871 made that year.
Your serial number indicates that your Winchester model 12 shotgun was made in the year 1914.
It sounds as if you have a Ithaca Crass model shotgun,that was produced in the year 1903 by your serial number.
With the serial number that you provided,your Winchester model 1912 pump action shotgun was produced in the year 1955.
with the serial number that you have provided,your Winchester model 12 pump action shotgun was made in the year 1916.
With the serial number that you have provided,your Winchester model 12 pump action shotgun was made in the year 1947.
With the serial number that you provided,your Winchester model 1912 pump action shotgun was made in the year 1928.
Your winchester model 12 shotgun was produced by winchester in 1947.