The tuners on the small sprite are barely noticeable
At that scale they're incredibly small anyway. I don't really see a problem.
The smaller sprite would look better if you didn't use a black outline. It'll add more color.
You should use a dark blue outline around the blue.
I used a dark brown outline for most of it because the edge of it is supposed to be wood like the headstock. The metal-blue parts on the resonator are only metal up to the edge. See how the one metal tuning piece that's on the neck
does have a dark blue outline?