Proceeding further

There are some precautions one should take into account when trying to assemble a real working hardware model:

The servo motors are of different power and might require different power supply schemes, as the UNO board may not supply enough power, especially when powered through USB connection.
In real life it might be useful to employ a force sensor at the end of each finger and use it for stopping a motion. Such sensors could be read through analog inputs, therefore different setup for buttons (rearrangement and additional components) will be necessary.