Copco's cast iron was thicker, and the bottoms of the pots were cast iron, and not enamel. Too bad they are no longer made today.
Actually it turns out that it is made but probably not "your mother's Copco". I ordered some of Mario Batali's enamel cast iron ovens for christmas gifts and was surprised to see that they are Copco.
When I read this post it made me go check and indeed it is Copco--licensed (which I guess is "owned") by the Wilton Corp. And, as everything else, made in China.