My 66 also has curved side windows. So far all are intact. How did you break yours? I am trying to figure out if they break, from use or impact so hopefully I can avoid an accident.
have the metal trim pieces for your windows (mine do not use) and I believe they can fabricate a lexan or plexiglass alternative. They also carry all the operator hardware.
Go to Tom Patterson's website
and search the VAC archives for previous posts on curved windows. Use the webglimpse search at the bottom of the page- when I entered corning I had a lot of matches.