I have a Celestron Motodec identical to the JMI with a brand new Hankscraft gear head DC motor. Probably the last of these motors available to fit the Motodec. Cost me US $52 for the motor alone.
So if you are restoring an old fork mount or have a broken Motodec or Motofocus dc gearhead motor you may require this.
Here is a photo plugged into the Focus port as my particular model requires a stepper motor for DEC. Some models have a dc motor plug for DEC on the hand control
I am replacing the Motodec with a new stepper motor and so don’t require this. The Motodec only as I have no original brackets. I intended to keep this as a spare for the motofocus motor but I have way too many old parts.