There are Vukovic`s also in other parts of Montenegro. Vukovic`s from Piva and Vasojevici . But seems to me if you are shore that you family have some conections with Kotor that they are from Katunska Nahija a rocky and mountineus region up of Kotor. In 1890 all Montenegrinswho emigratedin South and North America used the way of Kotor . In Kotor was the nearest port for them and trumit Kotor passeda closest way to bether future. There is no region of Gorski Kotor in Croatia , the region is named Gorski Kotar and not Kotor so you failed mr Jerin.
So miss you can get documents easly if you go to Kotor archivium , I can do it maby because I live close to kotor but I must have an autorisation from you to copy . My e mail is Stojovic@cy.yu