I have connected the "D-9" mark (D standing for distiller) to Old Quaker Company, Schenley's Old Quaker Whiskey, Schenley decanter with floral embossing and Golden Wedding. No doubt the company registered as #9 marketed a number of brands.
I would search around for magazine ads from the 50s to see if you can find such a bottle pictured.
Let us know what you find.