Dr. D.H. Seelye & Company
Dr. D.H. Seelye produced Liquid Catarrh Remedy and Dr. Seelye's Bronchial Syrup in Freeport, Illinois. He must have used general issue proprietary stamps until October of 1865, when his eight-cent private die stamp was first delivered. 22,000 of them were printed, all on old paper, and the last delivery date was January 18,1866. No trace of Dr. Seelye or his company can be found after that.
For that small number, the stamps are not difficult to find, nor are they expensive.