Hi,
Here is my biggest FreeCAD modeling project so far : a hollow-body electric guitar.
The top and back have a arched shape, modeled from a point cloud I already had.
The tuners, however, have been quite a challenge for me ( the worm gears especially ).
So they're not completely accurate, but they look good enough.
Here are the bridge, the tailpiece and a pickup :
A view with the top removed :