Based on the Wringer Code system below supplied by member swestoyz (Ben) in a previous post, it looks like it dates to October of 1960.

"Starting in January of 1954, wringers used a standardized serial number scheme, with two letters after the production number. The First letter indicated the year, and the second the month. Please note - this list DIFFERS from the automatic codes of 1949 - 1965."

Year Code Month
1954 A January
1955 C February
1956 E March
1957 G April
1958 J May
1959 L June
1960 N July
1961 P August
1962 R September
1963 T October
1964 V November
1965 X December