This heart box and pin are based on the exploitable heart by emmett - http://www.thingiverse.com/thing:6190 Emmett's stl file was reduced in resolution and converted to an openSCAD polyhedron command. Emmett's 3D heart is more rounded than thing:226907 - Hearts.

heart_box.stl
heart_lid.stl
heart_pin.stl
half_heart.stl

OpenSCAD code is provided

Heart_pin.stl, heart_box.stl, and heart_half.stl can be printed directly on the build surface while heart_lid.stl needs support.

Two half_heart.stl prints can be glued together to form emmett's original heart.