Here is a freeby.
https://oldcroak.com/jem-manual/
Parts are not easy to get for the older Wico Jems. Most of the Pietenpol aircraft that used the model A engine ran an crankshaft driven magneto that was more conventional is design. The Pietenpol kit for the engine used a special head for cooling so they moved the mag.
An impulse coupling was built in to the Jem 1509 for starting. There is no other provision for a starting aid unless the mag body can be rotated and connected to the spark control in some way. Starting at full advance will eventually damage the starter due to kick back.