thank you for sharing this,
have an opportunity to test it my own the following days.
looking good but seems to be short, or its only me searching for mass explanations,
like brushes settings in different stages of the paint and such (tried some painting tutorials and this little detail very helpful).
you mentioned the first sketch for the idea, i dont want to be greedy, but it could help to see how it looked like, more or the less.

thank you again for your help and share,
you're really great