Fol, absolutely rare, would seem to be from Belluno, Folin instead is specific to Venice, Folini has a stock in the Sondriese, especially in Ardenno, Chiuro, Sondrio and Ponte In Valtellina and one in the Lucca area at Seravezza and Forte dei Marmi, Folino instead seems Calabrese Cosenza, Crotone and Catanzaro in particular, should derive from apheretic forms, more or less truncated, or names or hypocorisms of names like Christofolus, Garofolus or Buffolus.
Buy a heraldic document with your coat of arms
You may be interested
Verba Volant, Scripta Manent