According to a 1961 article in the Kansas City Star, the Paper Supply Company moved into this location in October of that year. Immediately prior to that the Thompson-Hayward Chemical Company was located here since 1917 or so. It is not surprising that THCC moved out of this location and dissolved their operation here since they just suffered an industrial accident in April of 1959.
Paper Supply operated as a mill agent and distributor of printing, industrial, and specialty papers. According to this source, there are documents on file for the 1980 purchase of Standard Paper and another transaction involving CDA Papers in 1986, so it's reasonable to assume that the company remained strong. It shouldn't require any stretch of reality to spot several boxcars of paper on their spur during my intended modeling period.