A quick search revealed these articles!
There was one done not too long ago(?) spring by Chapter-9 members.
http://www.acmoc.org/bb/showthread.php?22385-Chapter-9-Caterpillar-Twenty-Two-Electric-Start-Conversion
Here is another!
http://www.acmoc.org/bb/showthread.php?15688-CAT22-flywheel-ring-gear
Here is another!
http://www.acmoc.org/bb/showthread.php?2085-Cat-22-Electric-Start