Not their '64 Dart lenses, but I've bought other lenses from them and been very happy with them.
I can't imagine why someone in Australia would tool up for a local (Australian) market with a lens when there are only about half a dozen of these cars 'down-under'?
I did email Rick yesterday regarding the gap in the ring, he did reply promptly, but the response was along the lines of
"spoke to Dave, nothing can be done to improve this".