Thank you so much for uploading these files! This was my first doll. *I didn't know ball joint dolls were a thing before I saw this. It was a lot of fun to make, and to print accessories for. Defiantly a HUGE cost savings compared to the expensive dolls.
There was A LOT of sanding involved. I cut pieces of sandpaper into small disks to use with my dremel on low speed setting. I completely smoothed out the model starting with 80 grit, then on to 120, 220, 300, 400. I cleaned it with isopropyl alcohol, then I sprayed with Rustoleum filler primer in a thin even coat. Give it 24 hours to dry, then VERY LIGHTLY sand with 800 grit sandpaper. This is to remove the rough texture of the Rustoleum filler primer. Then spray with a Krylon matte clearcoat, allow a few hours to dry, and she is ready for stringing. The doll is super smooth, except for the hands which are too awkward to sand properly.
I used Meshmixer to generate supports.