I think we can safely speculate that Henri Farny clarinets were named after the French-American painter, Henri François Farny. This parallels Guy Renne, Paul Dujardin, Jules Legris, and other stencils named for various French artists who were better known around the turn of the century.
Gunckel is certainly the odd case.
I have one complete Farny example, also an Albert that is similarly marked on the bell (nearly obscured by deep scratches) and the upper joint. That one is marked Heri Farny & Cie, as if there really was a company, but there is no record of such a company in New Langwell. Perhaps the "& Cie" refers to the USA Wurlitzer company that distributed Farny branded clarinets?
I obtained the Farny along with an F. Delarue A Albert (in very rough condition) and F. Delarue is another enigma brand. Some sources identify François Delarue as a maker, others as a stencil. Complicating the matter is the concept of "stencil heaven". A good number of actual makers appear to die only to be reborn as a stencil brand owned by a successor. The better known examples are D. Noblet and L.Lebret, but certainly there must be many other "stencil heaven" events.