Socket & tip for custom partial finger replacement

Updates to this design as of 11/6/14:
- Increased the size of the cable & bungee channels
- Improved the shape of the fingertip
- Increased the thickness and durability of the structure to prevent the fingers from bending backwards
- Added bars to tie the cable & bungee off too
This is the first in a series of 3 things that, when combined, can be used as a device for some partial finger amputees missing more than half of their finger. It's customizable so that it can be adjusted to the size of the user's hand and fingers.
Included in the "files" section is a PDF document with a measurement guide and instructions on assembly.
* All measurements must be in millimeters.
This thing contains the socket that fits over the finger stump and the artificial finger tip.
A video showing someone trying out the device can be seen here: http://youtu.be/WlfS02OAKcU
I see this as just a starting-point (and a rather rough one at that). I would love for other designers to take the s