Both are beautifully done. The black-and-gray color scheme on the stock version reflects what I've been considering for my 1/16 Mercedes SS, based on a surviving car, and confirms to me that's the way to go. What gray paint did you use? It's just what I need.
And NATO black for the convertible top is a real discovery for me, since it looks like a more realistic, less intense black than typical model paints. Could be a good choice for vinyl tops, too. My Mercedes top might require a slight mist with dullcote, though. And I love the attention to detail with your use of the wood on the convertible frame. As for attention to detail, the period license plate shows how much care you put into this very sophisticated build. Do you have other pictures of this car?
Nice work.
EDITED ADDITION:
Okay, so I went to your website. I am officially blown away. You should have more detailed photos for each build. Unbelievable.
http://www.bikelab.net/models/home.html