With all due respect wldmn, I understand your motives & they are good!
I just think you are looking at this in an idealistic & possibly simplistic fashion.
If one invents a vigilante group, it is hard to predict , what some of the egos amonst it, might deem acceptable or a fraud.
The example you sight as a mislabeled kukri to a collector of arab Jambiyas is a fraud!
If you type japanese sword into ebay, probably only one percent of them are real, hunting through the dross of what are obviously fakes to find the pearls are what keeps the buyers thinned down, if all the japanese swords are real, every dumb sonofa*itch, will be bidding on them, and the prices will sore.
Also who is going to police these unpaid charity vigilanties? after all most people who will become involved in this group, will be buying & selling such items, so will thier friends!

What will thier true motives be?
I think its a nice idea but could lead to a lot of problems in practice.
I think you have done well to get the ball rowling but I fear it will drive the prices up, much to the delight of those dealers & collecters who already have a large stock of items.
I hope I am wrong & you are right in how this pans out, but unpaid charity vigilanties inforcing thier say on others, seems highly risky & suspect to me.
I wish you good luck with this , I think you will need it!
Cheers,
Spiral