Hi. I have a (extra) flat 19J Touchon (Wittnauer) PL watch in a platinum case . The movement is quite thin, 1,86 mm. I am curious about the case mark, does anyone recognize it? I have heard the thin Touchons came in three different thicknesses. 24, 20 and 17 12th's of a millimeter, is this correct?. Is my mvt the 24/12 variety. It sort of falls in between the 24 and 20 thicknesses.