On Sat, 25 Sep 2010 13:59:26 -0700 (PDT), wrote:

Also, trace elements can do odd things to
cuprous alloys, how complete was the original chemical analysis?
Thinking arsenic, tellurium, selenium and maybe silicon and
phosphorus. Might have silver and gold, copper refining wasn't that
advanced to remove all traces of those, but those shouldn't do a lot
to the alloy properties.

If you search for alloys close to a 90/10 composition on the matweb
link I gave, it appears that just a trace of phosphorous has a big
effect on formability.

--
Ned Simmons