I don't know anything about the Szonszor spelling, but it's true that the Polish pronunciation of "Gasior" is "GON-shore." Our Gasiors did a funny thing when they arrived in the U.S...they immediately tacked on an "-owski" so there would be no mistaking them as anything BUT Polish! We believe our Gasiors/Gasiorowskis came from Zakopane, and possibly not until 1890-1900. Their names were Stanley (Stanislaus) Gasior and wife Katarzyna Stasiowski Gasior. Good luck in your search, and do let me know if any of this sounds like a good lead for you. I can try to find more info if it seems helpful.