as it is way more perfect than any other representation and probably the frist T1 skeleton ever attempted, it might be ok to be slightly nitpicking, considering its size, prize and overall greatness.
while forearm's main bone finally isn't cylindric (as it usually is on statues and figures), the angle between it and other hydraulics looks almost zero, while it should be i don't know, 10 degrees maybe. well, more degrees than 1-2.
at least according to a stop-motion puppet, which i doubt would have less/worse details than a full-scale.
see, the forearm shape is very triangle. the biggest pipe should be far from parallel to other 3. while they should be moved further to the outer border of that big shield right before the elbow.
also those bases of 3 hydraulics don't have that extra widening ring on each of them that were in the movie. they're just cylinders at their beginning, while they shouldn't be.
and i don't understand why there are no strings inside the forearm (going through its whole length to the fingers, he operated them in arm repair scene) and no thumb connector in the palm.