I went through the depletion gilding page and I aminterested in 2
things. First, can metals be gilded with AuCl3 without precipiting
the gold powder like gold is gilded onporcelian by fire gilding.
regarding your first question, in India the gold jewellery polishers
(mainly Bengalis) used two types of processes:
a) Depelation (in local lingo Chatka) where in the alloy on the
surface gets dissolved in hot acid pickle and pure gold remain.
b) the other process (Rang) where in the gold on the surface too
gets dissolved (presumably in Aqua Regia and becoming AuCl) and the
same gold gets deposited on the surface by addition of some salts or
since i personally have not done either of the processes, i dont know
much about the process in detail. but i think you may find some
Bengali polishers in Kathmandu and know more from them. they may be in
and around the jewellery market in your area.