An unexpected discovery in Google Books. I tried searching for a Latinized version of the name Cansino (Canzinium) and other variants, and came across a compilation of jurisprudence from Florence published in the 1700s. Salvador Cansino is mentioned in connection to certain business loans and maritime operations (I have not attempted to translate it yet). Maybe it is a potential source of information on Sephardic merchants? Worth a try.