Add / Improve Details on existing STL 3D File Model to improve 3D printed Model look when sanded and finished

We have an existing STL file of a human hand, overall the model is good for our needs but requires a little more detail and/or definition for the creases in the skin at the joints and also around the fingernails, these details are not very clear when the file is 3D printed, as almost disappear completely when the printed model is sanded and painted

We require 3D artist to sharpen the existing detail and add additional details if required please see the attached file for areas to be improved, STL file can be shared upon request

Please note we require basic details to be added the details just need to be well defined - we are not looking for a work of art!