Genuzio Carletti, in Italy, had a working relationship with Joseph Settin in New York. Carletti made instruments, and Settin set them up and sold them. The two labels above were found glued one on top of the other (the earlier dated one hidden under the newer). It appears that Settin wanted some way to indicate the collaboration, and wasn’t sure how obvious to make it, but ultimately settled for the less-transparent solution.
A friend of mine remembers visiting the Settin shop in the 60s. He said that it was a messy place with incomplete bits of old violins were strewn around, and it appeared that perhaps new whole instruments were being made to include them, John Lott style.