Hi Frank
Just thought I'd let you know my mother's maiden name is Vlach. Her father's name was Vlah, which was pronounced like Vlak. He came from Kastav, which was part of Austria when he was born, then became part of Yugoslavia, and is now part of Croatia.
He moved to Italy, where to get the hard sound of the k they changed it to Vlach, as Italians pronounce ch like k.
I don't know if it has any meaning, but hope this is some help to you. I also have some relatives in America who kept the original spelling of Vlah.
How do pronounce it ch as in church or like the k?
Hope to hear from you soon.
Rossana