I came across a Cigarette Tax stamp from Ohio and I found it it be interesting. There is an overprint; Dow Drug Co.

on a cigarette tax stamp

Does anyone have any experience with this type of revenue stamp and the knowledge to educate me why DOW would use this, Pretty Please?
Also, any idea what year this is from, and what type of catalog one with little experience would use to I.D. these stamps? I have tax stamps for Cuban Cigars I need to look up as well.

