I want to share a resource with fellow owners. I recently purchased a '93 300CE Cabriolet and needed a few interior parts, including the rear window trim piece that was impossible to find. I was fortunate to find OctoClassics (https://octoclassic.com/). They are reproducing rare plastic auto parts using 3-D printing. I have been very happy with their products.
Another excellent source is Classic Trim Parts (https://classictrimparts.com/). I purchased two vanity mirrors from them. They come in a wide variety of colors.