'Zackly! The problem is that I run into people that still quote AA, bible and verse. My last attempt to update AA was my wartime Pebble Plomb expose and Plomb No. 18, 19, 19-A, and 19-R catalog dating analysis. I have now given up. Being wrong is excusable, especially in this hobby, when so much depends on references. Being wrong when one refuses to accept and consider references one doesn't personally own, or substantiated research and analysis one has not personally conducted, is inexcusable.
I don't know, but Bethlehem Spark Plug Co. used copper plating on hex drive socket drive tools in the antique era. Otherwise, I would suspect either BeCu, or patina. I have a number of tools that look coppery. Something about 1940's Williams-era steel in particular seems to go coppery. Whatcha got?