1965 C337 "Alternator not charging" light

[cessnadriver]

Dr. Dave. Question. I was revisiting your reply about your circuit breaker panel re-wiring. I noticed that there is a narrow jumper strap between the lower row and the second? Do you not have a Avionics master switch? Or is that jumper connected to a switch instead of a breaker? I started ordering my electrical parts, but waiting for Zeftronics to verify their part number for my C337's ACU?
When you installed the new ground cable from starter to starter did you need a 1/4" or 5/16" hole in the terminals? I'm think/ordering 5/16"??
Many thanks-again.
Regards, BILLS