Hand painted Deco graduated satin glass vase

Originally one of a pair, this required some cleaning (and still a way to go). In cleaning accreted dust and smoke off it, it became clear that it is a glass vase (only joking!), and that the hand-painted decoration is quite delicate - a lake- or river-side scene with wispy spruce and boats.
It is pink graduated down to amber/lemon at the bottom.
The rust looks like it's there to stay unless anyone has a hot tip?
It is hallmarked HP&S, London, 1929.
It is 16.5cm tall.