Hey bro, heck of a task you took over. I would suggest you consider adding some beefier lines throughout and play with line weight to separate the items as there are many color with very similar values and this will help you to separate elements and create more field depth.

Then I will do a second pass of color and maybe a final session of white.
I manage to cover a lot of tattoos when I had my shop with Mom's white and Eternal White. To me one of the best whites out there.