RD#42 is the Fairfield Distillery in Fairfield, Kentucky, which is a wide spot in the road a few miles east of Bardstown. The other, more famous distillery in Fairfield was Henry McKenna.

The Fairfield Distillery was built in 1935-36 by Lewis Guthrie. McKesson Robbins bought it in 1942 and used it to make alcohol for military use (not for drinking). Schenley bought it after the war and resumed making whiskey. Chapin and Gore, and Old Jim Gore, were brands owned by McKesson, which Schenley continued to produce. The plant stopped distilling for good in 1955 but continued to age and bottle whiskey there for some years thereafter. Heaven Hill bought the operation, including the brands, and used the warehouses for a while. Everything is gone now.

This all means is that this was distilled at that plant prior to 1955, probably between 1945 and 1955.