I purchased this in Nepal many years ago when working there in the mountains. It is either from the Himalayan princedom of Mustang or from the remote area of upper Dolpa / upper Dolpo, I forget which. Both areas are very high-elevation ethic Tibetan areas of the Tibetan plateau, but on the Nepalese side of the border.
I don’t know if the metal is real silver or something else.
There is some bug damage in the wood on the underside (see photos). However, you can still enjoy the cup. The damage is only visible if you turn it over and look carefully.
The metal could use some polishing. But the darkened look is nice too.
This is definitely a genuine antique tea cup from the Tibetan Himalaya.