A couple months ago I printed the modular fiddle and loved it, but found the angular body wasn't super comfortable for me to use without a chin rest, which is how I roll sometimes.
So I threw it into Solidworks and modeled up this rounder stylized version that's approximately the same size with the same face and back curvature, bass bar, and soundpost. Along with styling it a little I also added very very shallow indents in the neck, placed in the 4 regular finger positions. They're only 0.3mm deep and very thin so they don't get in the way of playing but indicate where to put your fingers if you need that and don't want to put tape or stickers on the neck.
I also changed it to use regular guitar pegs and to accept a 3/8" aluminum rod in place of a carbon fiber tube, since aluminum is cheaper and easier to work with.