Hey california-william, you're talking common-sense and logic. But you will be beating your head against the wall, because the human psyche wants "so hard to believe" in any sort of fanciful treasure chests, suits of armor magically sitting undisturbed on cave floors, and so forth. Once you get someone giving a "lead" to a "treasure story", people will not find reasons to dismiss the notions, with common sense. Instead, they subconsciously bolster them, to the point of being iron-clad (because he said that she said that .... etc...). Why do you think all those treasure mag's from the 1960s and '70s sold so many copies? You know, the old yarns about the dying miner, the lone survivor of the indian attack, who drags himself into the saloon, spills the story of fabulous riches, giving a few clues, but dies before being able to return to recover the "lost mine" blah blah blah. We gullible md'rs want so hard to believe (lest we be "left out") that no amount of counter-persuasion works.
You're right about the "leather jackets" being the extent of their "armor" in the pacific northwest. Because they only had to repell indian arrow, not bullets. For example, in the Carmel Mission museum (the 2nd of the 21 missions), is an actual 1776 De Anza party chest armor, made strictly from leather. Multiple pieces steam-pressured and sewn into a type of chest armament. That particular excursion in 1776, was well financed and supplied Spanish excursion into Alta CA, at the time. I suppose ship traffic (which had the luxury of carrying more weight) could have had heavier stuff to bring to the new world. Still though, realistically speaking, manufactured goods were in short supply here, as cargo space was very precious and valuable, EVEN on ships arriving to re-supply the CA missions and presidios. We were at the remotest parts of the known-world at that time.
I've found Spanish uniform buttons, and other knicknacks. Even a sword hilt (however that *could* have been mexican era, who knows).
Not saying things aren't possible, or couldn't have occurred once somewhere ........ but just saying that in CA, you're going to be really lucky even to get Spanish era reales, at most, if you're really hardcore. The day and age of stumbling into caves (that coincidentally no one ever saw before, doh!) and just seeing treasure chests and suits of armor there? I mean, c'mon.