50 years, it's time to upgrade.
It is rare to find equipment from 1959 that is in good shape.
MOST of the damage to the system comes frome 50 years of uinqualified people adding on crap.
It's time for a new service, panels and grounding/bonding. It's also a good time for GFCI breakers on any ungrounded recep circuits. Also, do a check of your ceiling light jboxes. 50 years of 100 watt lbulbs will really cook the wiring.
Add smokies too.