We used to make things in this country. # 122: Carter, Cummings & Co., Windsor, Ontario

A product called "Ozonol" was made by Ozonal Laboratories in Lond, England and received a British patent in 1932 for "Improvements in or connected with means for disinfecting mouthpieces of telephones, speaking tubes and the like."  The product was also distributed by the old pharmaceutical firm of Butler & Crispe:  

1939

So, it seems likely that Carter, Cummings & Co. made the ointment under license.  I can find little on the history of the company, other than it was in business as early as 1918 but dissolved at some point in the last half-century.

The Canadian tin proclaims the virtue of Ozonal for the treatment of sun burn and hemorrhoids, allowing the user to apply it both where the sun does and doesn't shine.  Note that one of the ingredients is lead oxide.  Probably not a good idea, given our current understanding of the toxicity of lead compounds.