"Currently it is theologically the Episcopal Church [i.e., the Protestant Episcopal Church, official title]." 

Quite right, Marty E! The Old Catholic Church is different from the Catholic Church, theologically, ethically, and in ministry. And none of the great Catholic cathedrals throughout Europe are even remotely attached to the "Old Catholic Church" -- Cologne Cathedral, Munich's Dom -- any Catholic Dom in Germany, any Cathedral in Paris, Brussels, Vienna, Prague, etc. even remote Aachen Cathedral-- none of these cathedrals acknowledge the "Old Catholic Church" as a peer institution. So why bring it up if European Catholic communities dismiss it. Architecturally  and even demographically, it is invisible in Europe.