mag wheel hub caps
You could try here.
http://www.hubcaps.org/dart.html
The $90 each may look high but if a member here has a set I bet they would be close to $400.
I got my 68 Wire Wheel covers from them. The quality was outstanding, absolutely ZERO road rash, fully polished and repainted.
The wheel cover is a bit dusty and dirty in the pic. Anything that looks like damage is reflection and fingerprints.