At least with the posting to Rec.crafts.metalworking. Most people here will have a pretty good eye for handedness on threads. :-) Probably the woodworkers, too, though I think that left-handed wood screws are pretty uncommon. :-)
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And they probably used a desk ruler or a tape measure, so getting a reading that accurate would be pretty unlikely. :-)
Well ... brass and bronze look very much alike, especially when clean. They develop somewhat different patinas, but the real thing is strength. A tool should be bronze, not brass, and I would be willing to bet that this one is bronze. If anyone could track down the logo on the handle it would probably show up listed as bronze -- maybe phosphor bronze, or maybe even Berylium Copper.
Enjoy, DoN.