I don't really support mods to GOF 2.5, but just supply it as it was when the modders abandoned it.
But prior to starting a game with Davy Jones, open the Programs\characters\RPGUtilite.c file and find the case: "will" section. Edit it to look like this:
case "will": pchar.Ship.Type = GenerateShip(SHIP_CursedDutchman, true); pchar.money = 30000; break; case "davyjones": pchar.Ship.Type = GenerateShip(SHIP_CursedDutchman, true); pchar.money = 30000; break;
Save the file, then start a new game.