Re-polarize your generator before starting engine!
Momentarily short the generator output to battery hot (the side not on ground)
If you skip that step the generator will try to charge in the opposite polarity and will draw a massive current and melt something or burn out the generator or regulator or all the above.

Switching the ignition coil is ocd and not required
The ignition system is operating as an AC circuit and the polarity of the leading cycle is not important for the purposes of making a spark.

If you had an original radio
Most would work on either ground
But some early synchronous vibrators required known polarity such as Autoradio model 48 and 490 from GM used in 1947-49 trucks in Canada, that radio needed the vibrator rotated 180 when swapping the ground, there is a warning sticker inside the radio as if you could find it! Lol
USA radios could work on both ground polarities because they all used non-synchronous vibrators from the beginning

In Canada the model 500 and later switched to non-synchronous style like the USA radios.
-s