Based on the pickups in a Gibson Epiphone. Sadly, I don't think it could be MakerBotted, unless it was done in two pieces. It's intended to be laser-cut in layers out of cardboard.
Of course, real bobbins are dirt cheap (about 2.50 USD), but the .scad file can be hacked to make custom bobbins (super-large, super-small, different magnet counts, etc.).
Not yet tested.