This is a new one on me, convertible???
I like the concept drawing.
It showcases the B pillar flow.
A "spoiler" on the windshield frame top also helps with air into the passenger compartment.
You could probably make one yourself easy enough with Valiant or Dart convertible windshield parts and either fabbing a fairly simple targa or modding a real vert top.
If I had an early Cuda with a rusted roof, I'd sure think about it.