I'll go along with the ebay listing's age. From what I remember of my first bike store browsing and early Los Angeles Wheelmen rides, bikes like that were in circulation before 1970. Huret Luxe derailleurs, Zeus cranks, also many Gransports of that age had seatstays that completely wrappped over and connected a'la Raleigh Grand Prix.
David Feldman
Vancouver, WA
Was young enough in the 60's so that I actually remember them