Here is a resin 64 Chevy Impala uptop for the AMT Kits. These don't come with the rear glass.
(these will fit the REVELL 64 impala with a little modification)
Resin 1964 Impala Up-top for AMT kits
As with many resins, you'll need to clean up any excess flash, pin holes and wash down with a good degreaser to remove any oils from the molds. Also before paint, check fitment as resin differs from plastic parts.