First draft in black. Some issues:

• The head fittings were too round and slipped easily out of the sockets.
• The servo arm holes printed poorly and filled in.
• The last two tail frames were not probooleaned correctly and did not fit over the vertebrae.
• The tail screw covers were too fine and snapped. 

In the second draft (white), they were adjusted:

• The head fittings are now cones rather than hemispheres, and are futher apart so that the pressure that's keeping them in there is higher. This helped, but now it is a bit tight. I will continue to iterate. 
• The walls of the eyes were thinned to allow more light through them, but PLA is still pretty opaque. I will have to do a test with internal LEDs. They are at minimum thickness at this stage and if they are still opaque, I will consider removing them altogether and sculpting them out of thermoplastic instead which is semi-transluscent. 
• The tail frames were cut correctly and now fit over the tail. 

The third draft (yet to print), has had these changes:

• The recesses for the servo arms have been made deeper.
• The tail screw caps are thicker and longer
• the cavity of the head fitting is now set deeper and is more concave to allow the fittings to move more freely within the cavity, but not fall out. 

When my model is completely functional I will post a new file.