I had talked with a collector of Minn guns a few years ago. Forgot the gentleman's name. If I remember correctly, the Kennedy's were in business until sometime in the early 1960s. I do think that they stopped building guns a good many years before that, though. Perhaps in the 1930s???
The one example in my collection, in need of cosmetic restoration is a very well built side hammer gun.
Best,
John

Humble member of the League of Extraodinary Gentlemen (LEG). Joined 14 March, 2006. Member #1.