This is a progress shot.  I am going to put my face onto the original painting.  I will cut out my face, adjust the size of it, and match the skin tone.

I downloaded craquelure from CG texture .com.  I put it on my face to make to make it look like old painting.  This is my final work.

This is a progress shot of You & Four.  I am making 4 subtle changes: 1. The facial expression.  2. The hair style and added ears.  3. The color of notebook.  

4. The hand motion.  

This is the final work.  I made 4 subtle changes first, and then I added craquelure texture on them to make them look more natural.