My ground electrode was compromised too. The first night I was here I lit myself up on the electric cook top, standing barefoot on the terrazzo floor.
I found the ground rod clamp corroded almost off. I fixed it that night with a <YIKES> hose clamp and the next day I bought another rod a clamp and some 6ga wire.
I tightened up all the lugs and basically went over the whole service. That was when I noticed the separate service conductors were coming in their own 1/2" romex connector in the side of the panel.
