In the 1950s and early 1960s, Ruddock's concerns shifted from the activities of Italian merchants in Southampton to a broader investigation of Italian mercantile networks and businesses in medieval Europe. She intended to produce a "big" book to be titled Italian Merchants and Shipping. Around 1965, she claimed to have made a discovery in the archives of a Venetian banking family: documents relating to John Cabot's early activities, including a loan that the family advanced to him .Evan T. Jones, "Alwyn Ruddock: John Cabot and the Discovery of America", Historical Research, Vol. 81, (May 2008), pp. 235–236Evan T. Jones, "The Quinn papers: Transcripts of correspondence relating to the Bristol discovery voyages to North America in the fifteenth century", pp. 13–17. For at least 25 years, she was promising to produce her Cabot book "soon". In 1992, she undertook a formal book contract with the University of Exeter Press.
