The threads on your hub may indeed be French. Which hubs are they? Normandy? Campagnolo Tipo? Kind of unusual that a Regina would be original equipment. Most, as I remember, were Atom. Mine was, anyhow. New Regina Corsa freewheels, especially with those larger cogs, are not too easy to find and expensive when you do find them. Did they have to completely destroy the freewheel to remove it? Any of it salvageable? Bob at Freewheel Spa may have something that will work for you, and is a swell guy. A member here too.