A few things to consider re the matchbox specimen:
1) First, you have to put your mind back in the day. During the western mining era, gold in all forms was money, literally, particularly in scarcely populated regions where more convenient paper money was not as accessible or well-trusted. Gold was the coin of the realm, as they say - dust, nuggets, ore, minted specie - all forms were accumulated, hoarded, traded, whatever. It was a common, accepted way of daily life that we in the fiat funny money world might attach a romantic stigma to that didn't exist for those folks back in the day. Gold was merely money.
2) When the Anglos first invaded the western states, and for many years afterwards, gold miners often led the charge and mines that yielded rich ores (by today's standards) were not uncommon. Nice to have some rich ore, yes, but it was not necessarily revered as some sort of "legendary" commodity - it was just money. Placer, of course, was much more common at first, but then came lode mining and the high-grading (legal or otherwise) of ore with native gold visible ("picture rock", like the matchbox stuff). The practice was common everywhere that rich ore was found and mined, and for many years that was in many places throughout the western states. As people moved on, they took their stashes with them. As you said, Jim, it was like an early savings account, but hard money not electronic credits. Folks ought to know that the practice of high-grading picture rock from lode mines was still alive and thriving at least into the 1970s - I know this is true because I participated in the practice myself. The point is that producing gold mines often yielded picture rock which was commonly hoarded and traded when those mines were working.
3) The matchbox ore is quite tasty, but by no means unique. Despite opinions to the contrary, identifying the source of the ore would be virtually impossible unless you found the mine it came from and the pay streak within it to compare with. There is no complete database of ore specimens available from western mines - not even close - to use for scientific analysis. Nice theory, but very likely not gonna happen. That matchbox ore could have come from some yet to be determined location in the Superstitions, sure, but it also could have come from the San Juans in CO (that's where I worked and saw much similar picture rock), or other mines in AZ, CO, CA, UT, MEX, wherever. Just because the ore's seller claimed it was from the LDM doesn't make it so, but it certainly may have increased its value. If I were to sell you an old Stratocaster guitar worth a thousand dollars, I might get ten thousand if I could convince you it once belonged to Jimi Hendrix, eh?
Putting aside the boatload of lore surrounding the LDM, based primarily on peoples' "testimonies", my conclusion is that Waltz - a retired miner and Phoenix chicken farmer - may have owned a cache of nice gold ore that he accumulated during his active years. To bolster an old man's image and standing in the community, he may have bragged about a fabulous lost mine in tough terrain that will, conveniently, never be found. I will gladly change my opinion when I see a reason to.
As IF corporate America needed any more generosity...
Merry Christmas to you all. 
