This subject comes up from time to time on md'ing forums. But I think it's only true if you sell it. Not by merely having found the object(s). Right ? And heck, Ebay (bless their little hearts) is already collecting taxes on buy/sell these days. So ... what's the worry?
And yes there's other ways to sell where no one's issuing 1099s (person-to-person transactions, like on craigslist, or to smelters who don't bother, blah blah).
Here's the bottom line : Our md'ing forums are FILLED with show & tell, where we show off our trophies back and forth. Right ? EVEN SOME VERY VALUABLE stuff from time to time. And I see guys show off their melt value checks from refineries (who maybe aren't issuing 1099s ?). Or persons who've shown staggering amounts of clad totals (that ... technically ... are supposed to go on your tax returns, since you're gonna go cash that in for some Benjamins).
But let me ask for forumites here : Has ANYONE EVER HAD AN IRS AGENT SHOW UP AT THEIR DOOR ?
I mean, do we *really* think that the IRS is monitoring geeky forums like ours, to see who found and then sold a goodie ? Trust me : They have bigger fish to fry. So : Continue to boast away