Not sure but I think the choke lever comes off the choke shaft with a setscrew or similar.
Do you have the style of magneto with sliding pieces? My experience with these is that they need a light oil. Grease can harden and gum them up so then don’t track the cam.
Cracked coils really should be replaced. Yes, you can coat them but the results are unreliable. Assuming you have the 7/16″ core coils, OMC coils can be put on the Wick laminations. Usually the lams are riveted to the stator plate and you don’t want to disturb their positions.