Hi Dan,
I always test images with facial ID software. I used to use MS Azure to get a score. When it scored 0.5 or above it said it was the same person. But now I use the MXface (demo).
With Your Voshart Somerton man with MXface.ai it has 0 confidence they are the same person whereas the sketch by SketchCop it has 100% confidence they are the same person because he remained true to the facial landmarks in terms of facial ID.
You should recreate your AI sketch training it with images of Carl at 18 and 16.
https://drive.google.com/file/d/1HxiYBHT2iYtFHJyQZA7IHzn8yyyWn0vv/view?usp=sharing
https://drive.google.com/file/d/1hcWU5Hone55b0C92FEoNZFy_Kc5NYA92/view?usp=sharing