Extraction Challenge: WIP II

So, I can't believe I've been working on this for a little over six hours now and am this far in already. Time has really flown, but I think I am gonna call it quits for now, and for the sake of my hand. Time to sit back, relax, and have a beer.  So ttfn!

The original sketch and a cleaned up tonal application to the sketch, leaving the airships blank (so I don't over render just them,,,,I am getting wise to my own vices). To do this I have 3 separate layers on multiply using the same near sepia color at different levels of opacity. I also used a hard round #5 eraser at about 12% opacity to erase out some of my light values.

Here I am pushing the tonal ranges a bit more, and finally adding in some life to the airships. Still using the same base color over multiple layers set to multiply, and varying the % or opacity per level as well as 'brushing out' tones with the eraser set to 12% opacity. 

Finally I am sampling some colors here and using a mix of overlay and normal layers to 'wash' in my colors. I am sure there are better ways to color an image, but so far this is what's working for me, so I can't complain. I do plan to lower the saturation of some areas in the future. 

Above is the photo I am using to base my pallet on. Normally I love to use this color pallet, so seeing it in nature is awesome.