Thank you for hunting this down.  I've always suspected that wire from 
less common manufacturers (I got one from General Cement a few weeks 
ago) was of varying grades, but never considered W-C wires would be also.

I have seen some spools that were bare aluminum (usually with no label), 
but you are right most seem to be pot metal.  Pretty awful getting the 
wire off when the rims have been broken.

I will be paying more attention to these issues.  And if you uncover any 
more information, please let us know what you find.

Very cool that the plant is still there.  It would be fun to drive 
passed the next time I'm in town.

Angie Dickinson Mickle
Avocado Productions
Broomfield, CO