Sorry, its not pink, clear flint only (I must ditch the black paper). Acid etched mark on base - as shown in the pic., and this design first registered in May 1921 - and the 'Blue Book' shows 2 Nos. for this - 682592/3 - does this mean the stopper has one no. and the base the other?? However, the main anomaly is that I can't find 'STUARTS' in any of the books - they all omit the 'S - and those books which I have access to all discuss marks post 1924 - 'STUART' only. What wud the piece have been used for??? It is of some quality, as there is a decanter type no. on stopper and the base (on the neck) - No. 52. The top of the stopper is ground/polished, and looks very lens like. The pontil is also ground/polished. About 12.5 cms. tall and about 9.5 cms. at the widest, and lots of wear on the base.
Grateful for any help please, and thanks for looking. Paul S.