Unlike modern science, juries need not be impartial, or even certain of the results to come to a conclusion. Metallurgical analysis on chips would prove that the lower was forged on that particular tool. Past there, they can convince the jury that given the amount of use for the machine, chips should have long since disappeared (fallacy), or that tool marks from bits and mills would have long since been obliterated from the tooling (fallacy). If you mothballed your 8 year old machine with old cosmoline, ground down/polished your tools, and made sure nobody knew, things would be OK...
I'm not sure I'd want to take that much effort to commit a felony, though. The ATF will do whatever it takes, including lying and falsifying evidence, to secure a conviction. It's only that much easier if you give them something to start with.
WRT carbon dating.. I wasn't *saying* that you could use other isotopes, it was mere speculation, hence the word "conceivably." I was elaborating on the point that carbon dating isn't the technique to be used.
Green0: I can't find any reference to the ship in the pacific, but errors do occur in any scientific process. That's why evidence from the ship's log and the whiskey bottle would be useful. This is all part of the scientific process. Given that radiocarbon dating, and conventional techniques agree with the sane perspective on the coexistence of man and dinosaur, this is the best idea, until contrary evidence comes about. The Paluxy River anomaly/hoaxes have been debunked for some time now.