My recollection is that Fleischmann's became a DBA of Medley in about 1985-86.
The Fleischmann brothers, Charles and Max, started the company with a third partner in Cincinnati in 1868. They had two plants in Riverside, Ohio. The company and Fleischmann name were purchased during Prohibition by Standard Brands, Inc., which converted the assets to food processing, e.g., yeast. My source says it was Daviess County Distilling, RD #2, that they bought in 1940, not Rock Spring, RD #10, but it was one of them. I know Medley bought the brands in 1985-86. I doubt they bought any facilities. The Medley family didn't own Medley by then, but Charlie Medley worked there. When Glenmore bought Medley, primarily to get its brands, it sold that distillery to Charlie, which is the one he recently sold to Angostura. Since DSP-10 was available, Charlie took the number because that was his grandfather's place, so #49 became #10, and I presume it will be #10 under Angostura.