Thank you all for your help!
As far as I know, the cup is solid brass.  I'm pretty ignorant when it comes to meatals though.  Here's a pic of the cup in my posession.  I've never posted a pic before and the post preview doesn't show it but I'll try anyway.
 [img]
http://www.corriganfamily.org/gallery/v/Adventure/Misc/Sierra-Cup.jpg.html[/img] 
KenK, thanks for the lead.  I will probably call them, but the next couple lines of the news letter are a bit discouraging.
"... awarded an engraved, brass Sierra Cup. This wide-mouthed cup with handle, perfect for dipping cool water from a mountain stream, was developed by the AMC. Times change, and the Sierra Cup is no longer available (and drinking directly from that mountain stream is not advisable)."I think I'm hitting a dead end, but I'll keep fighting the fight.  I've posted at an AT Thru-hiker's forum as well and they haven't been able to find anything either.  Just a sign of the times I guess.  There are much better options these days.  If any of you happen to run across one, drop me a line.  Again, thanks a ton for the input!!
m