(UPDATED Dec 6th:)
Here is the painting process:
I started out with a toned gesso on the canvas, and applied the drawing...
To fix the drawing this time, I copied a process I just learned about while attending my MFA course's Fall session, out in Pasadena-- Kenton Nelson showed us his studio, and told us of his process of using clear gesso over the drawing, to fix it to the canvas and to maintain an undisturbed drawing as the paint is applied (drawings can get muddy and disappear during the first wet and brushy paint application. This way, the drawing can be seen if you rub off or sand down misapplied paint, without worrying about loss of detail.
The drawing on the toned gray canvas:
Basic "blocking in"-- applying the lightest lights and darkest darks: