Set of 6 Champagne crystal flutes with fine ribs in 19th century

series of 6 19th crystal flutes to sound perfect, clear and ringing, most likely Baccarat, simply cut from a belt of fine ribs. A careful inspection, one of the flutes appears imperceptibly different from the other 5, buttons of the foot, a few millimeters in height, barely-straighter. It is a mysterious mystery, these flutes having lived all their lives together, volunteer participants in each of the celebrations of this inspired family. Is it a flute ordered to replace a missing part, at the beginning of the 20th? It's possible. In very good condition. Height 17cm diameter 5cm. Brilliant.