Don’t have to peer at the fine print to see when this was made: if it ends with Harding, then it’s pre-1923.
McConnon’s Book? Well, let us betake ourselves to “Winona’s Fleeting Era of Eminence,” which went from 1865 to 1895, around noon. Says the history:
In 1885 an itinerant salesman came to Winona to manufacture and sell his liniment that he claimed was "good for horse and man". Beginning in a two room house, J.R. Watkins made and peddled his liniment to a growing clientele. By 1912 the Watkins Drug Co. was an international corporation with plants in Canada and Australia. The home office and main plant remained in Winona. Watkins products became one of the leading direct selling firms in the nation.
Another drug company, McConnon & Co. was also established at this time.
And that's about all I can find at the moment - there's a McConnon street in Winona, and a later lawsuit for mislabeled vanilla extract.