I’ve always believed that if, when the flywheel is up-side-down on the table….if you place a typical screwdriver against the magnets and it grabs and holds it….your magnets are OK.
Have you check the points for insulator-block breakdown? When then are dis-connected do they read zero or close ohms when closed …..and when they are open do they read “open”. ?
Is your spark plug wire new and/or in good condition? Did you ohm-test that?
Do you have access to a Merc-o-Tronic or Stevens coil tester? Ohm testing a coil is good but not entirely conclusive.