I inherited an 8X8X3 cake pan. I followed the thread about aluminum pans, but I still have a question whether this pan is still safe to bake with? There isn't any discoloration that comes off when drying with a paper towel. The finish is very dull and the engraved product name is barely visible. Does anyone know what year these were manufactured and where? I love the pan and would like to keep using it. Thanks.