I think the factory install and the orginal aftermarket kit used exactly the same parts, by Cars and Concepts. Just the location of the install varied.
Its kind of extensive, you take a complete section out of the roof to install the top framing. The doors get the window frames cut off, and larger glass installed. The weatherstrip for the doors above the window is different, and the rearview mirror trim gets changed.
You could pull all of it from a junk and put it on another car.
I think this is where the doors were developed that ended up on convertibles also.