Mark Mayerson has completed a long series of posts compiling animator identification on Disney's PINOCCHIO, along with framegrabs representing each scene. In this final entry he notes that at the end of the film when Pinoke transforms into a "real" boy it is somewhat jarring, (something similar happens at the end of BEAUTY & THE BEAST), because we are deprived of the physical model of the character we have grown to love. Both PINOCCHIO and BEAUTY are careful to wrap up the screen time because of this ticklish problem.
I never liked the "real boy" model for Pinoke myself, but I remember hearing that the animators had a hard time drawing him as human in a manner that would signify a dramatic change. About fifteen years ago I found and bought this rough drawing at a convention that seems to bear that out. This Pinoke is very appealing and retains the design of the "puppet" version, but perhaps too much. His hands in particular still have the doughy cartoon quality of Mickey or the Dwarfs and his face and hair seem little different. I could imagine it was done over several times before it was satisfactory enough to represent the change to a general audience. It must have been a tall order.
