Kai, i'm afraid this mendak looks like a lost cause to me. I'm not so sure you have a gold alloy there as much as plated brass, judging by the amount of corrosion. You could recycle the "stones", but from the chips and cracks i'd say it's possible they are not intans, but glass. Even if they are intans they probably wouldn't look right in a new setting considering how beat up they are. Fairly high quality mendaks made of silver and gold or gold plate with gemstones are still being made today in Jawa, pretty much in this style. My advise would be to stick this one in a draw and seek out a new one.
