Hey Bart! glad to see you still up and drawing mate!
I think there's some slight proportion issues, also I think it's better you either keep your lines clean or your values clean.. it's kinda half half and not very solid in regard to anatomy. Nice studies, but it's more beneficial if you give it more love! I like your pencil stuff more, they do look more loved, especially the faces. keep going with it mate! cheers, Min