"Steuer-Pimpel" (don't know the word in english, sorry).
Replace it with any suitable cylindrical piece of soft plastic. Suitable is e.g. the inner isolation of a coaxial tv/radio-antenna cable.
The length of the thing is essentiell for a correct function.
Especially avoid making it much too long, as that could eventually damage something valuable (the needle).
Inner diameter: about 2mm / 0,08"
Outer diameter: about 4mm to 5mm / 0,016" to 0,02"
Length: about 5mm / 0,02" , but the functioning length must be found by trial-and-error.
Here's a photo of an intact "Pimpel" in a Dual 1224, which got exactly the same mechanics as the 1225, apart from the motor.