I worked on the designs a little bit more.
Here is the version which is almost final, and some sketches of the character's body and anatomical details
Here I finally got his face right. This is the design I'm going to use- I think it looks a little complicated, but I feel comfortable working with it, I find it easy to operate with and the forms in it are connected in a way that should make them easier to draw from different angles.
This is the final design for the old man and the boy: