thanks for sharing, lots of information.
Many articles have been written, it seems cyclic, know your dealer, ask the hard questions and if the answer is not an unqualified yes, it is a “no”. Sadly, the numbers are staggering and sobering.
My personal experience with “N/A” jewelry dates to one tourist bracelet from around 1939, a piece Dad purchased and two Maisel rings with a pair of earrings that matched one of the rings, purchased by Mom for under $2.00 perhaps 1950?. These from a roadside stand, probably on Hwy 40, in Nevada, road trip heading east. The were all set with art glass. I purchased my first piece, 1973? unsigned, pair of dangle earrings, silver conchos. The next, another pair of dangle, with a dremelled DM on the back. Even then we were trying to purchase well; the next items were gifts from a Native American Art Gallery (the gallery was supposed to be representing the N/A artists) on Cannery Row in Monterey, CA.
Education is your best defense and networking. And after all this time, I still have my budget.