SPECULATION Differences in Robotic Hands

I've done some hunting around for this for a while and haven't been able to find anything. I've seen a few minor debates about it but I haven't been able to find any dedicated threads on the topic.

I've held off on posting this for awhile now, but here it goes!

I'm convinced that the robotic hand holding JJ's note and the robotic hand in the R2 scene we've seen in the trailer are not the same - but I want to be very clear and explain why. I've indicated a few of the differences below:


Purple: Joint is exposed on the "JJ note" index finger (displaying a cylindrical shape with a hole in it) while the "R2 scene" index finger is covered with a plate (although a similar cylindrical shape seen in the "JJ note" hand is underneath). Also, the hole in the cylinder in the "JJ note" hand is much smaller than the hole in the "R2 scene" hand.
Red: Fingernail indention appears on "R2 scene" thumb but not on the "JJ note" thumb.
Green: The length of the metacarpal is drastically shorter on the "JJ note" thumb than it is on the "R2 scene" thumb.
Pink: The shape of this plate on the thumb is curved outward at the top on the "JJ note" thumb while the plate is curved inward on the "R2 scene" thumb. This plate is also much longer on the "JJ note" thumb than it is on the "R2 scene" thumb.
Blue: The plate located between the thumb and the index finger on the "JJ note" hand is not present on the "R2 scene" hand.

I've studied both images for quite some time and there are also major differences with the knuckles, wiring, and many other intricacies that aren't noticeable at first glance.

To me it appears as though these hands are completely different. It may be due to the fact that the "JJ note" hand was unfinished or it was an early prototype and that both hands belong to the same character, or, the hands are different and simply belong to separate characters. Could the fact that both characters have robotic right hands hint back to the scene in ROTJ where Luke cuts off Vader's robotic hand and realizes their similarities?

As I mentioned above, I feel very strongly that the hands are different... but what do you guys think?

 

Hmm, try this link if it still isn't working http://s27.postimg.org/dai6wxk01/starwarshand.png

 

You could absolutely be right! I just thought it might be worth discussing.