Toughness the Sabo-Termite, eh. Poor fellow really gets the business in these ads. Well, that's what he gets for attempting to make things Tough, including liquor.
I still think was odd to make the enemy of the 5 Crowns "toughness," because it's not a word one associates with liquor, and thereby makes you think stuff might be a little tough, now that you mention it.
The word "tough" had a slightly different connotation in the 40s, though. Bad, wretched, and so on.