This is a Waterman Night and Day made in France. It is 5.5 inches long (11 cm) and has a sterling silver overlay. It is a cartridge/converter filler I thought these were made around a Man 100 (maybe even a 200), but this one doesn't look like any of those. Was this made on a different model? Also, any idea about when it was made? how much is it worth? Any and all information will be appreciated.