tyke ā Leapfrogging back a little, āSā is known as an alternative version of the =S= mark of John Stonier & Co., etched on to the glass at the Stuart factory. It's not common; I've only seen two or three examples.
Stonier's certainly supplied glass to the two original Cunard Queens, Elizabeth and Mary, and boxed sets were used as competition prizes, see
here. BTW that wavy line decoration was a Cunard exclusive, not specifically for RMS Queen Mary.
Bernard C.
