I don't know if this is much help, but Gouda, Edam and Alkmeer were the premier towns awarded 'weighing rights' (like 'market rights' granted in Britain to certain towns to have seasonal fairs/markets that brought in money and trade). The names of the cheeses came from the town's name. Are you asking about the origins of washed curd cheeses or just Dutch-style? It would be nice if you referenced the sources that you've found for the date.