My thanks to all!
It appears that the gluing technique might ne the ancient Indian
method called the Kundan method - though I can’t attest to the level
of skill in this instance.
"The entire technique of Kundankari lies in the skillful setting
of gems and stones in gold, which is rarely solid. Holes are cut
for the gems, engraving is carried out and the pieces are
enameled. The core of the ornament is made out of lac, a natural
resin. Later, lac is inserted into the hollow parts and is then
visible from the front, through the holes left for the gems.
Highly refined gold or kundan is used to cover the lac and gems
are then pushed into the kundan.
"To increase the strength of the joints and to give it a smooth
finish, more kundan is applied. Kundankari is such a specialized
work that it is carried by a group of craftsmen, each carrying
out a specific task. The chiterias make the basic design, the
ghaarias are responsible for engraving and making holes,
meenakari or enameling is done by the enameller and the goldsmith
takes care of the Kundan or gold. The jadiyas or stone setters,
set stones such as jade, agate, garnet, emerald, rock crystal,
topaz, amethyst, and spinel into kundan."