Ask also, if the location of the artist and the origin of the timber used is know. This would apply to the contemporary alternatives like Bondo , Agave or whatever. The person selling it to you should be able to answer your questions, direct you to someone who can or be honest enough to admit that they don't know. I think you can get a pretty good idea. But, don't assume they are.
All people can be wrong, it's a very human trait.
Believe me I know. Getting back to the idea that just providing people with an instrument and basic instructions on how to sound it is often used as justification for almost any act of blatant cultural theft. The market place is full of such examples. Although some companies and individuals have made efforts to turn this tide though various means, there are a few who's greed is so enormous that they have turned to off shore, third world manufacture and decoration of substitute instruments. Circumventing, not only the Australian Aboriginal communities, the Australian continent, but issues of fair labor and fair world trade.