After some months a little away from watches, (but always reading new posts in the forum), I'm back to "work".    A friend of mine bought a nice Cauny cronograph with a Landeron 248 and asked me to see its condition and to service it.     The watch and chronograph functions are working properly, but when I opened it I noticed some points of rust in some screws ann parts. Not very much but always disturbing to see:         I have already disassembled all the movement, (I'll show t