Repair Vintage WittierTtaktell piccolo metronome Brown Edition Winder Issue

Description

Vintage Wittier taktell piccolo metronome Brown Edition. Made In Germany.  The winder is moves backwards.  But to wind it, it stops before you can wind it up.  So the winder is not functioning properly.  The arm moves.  This is sold AS IS.
Photos are part of the description, please feel free to ask any questions you have.
Item is pre-owned and acquired at estate sale and may have been used. I did not attempt to clean. Expect to find minor signs of use. You are purchasing as is, any flaws I found are noted. Look closely, what you see is what you get. Believe may be vintage age.