A Ruby and Diamond Christmas Tree Brooch/Watch, by Mauboussin

Designed as an 18k yellow gold Christmas tree with bullet shaped ruby candles and brilliant-cut diamond details, to the watch at the back of the base. French assay marks for gold and platinum, circa 1940.
Unsigned, no. 3540
An identical piece is illustrated in the book Mauboussin by Marguerite de Cerval, p. 261.