[kbsparky]

Typical 70's installation.

It would appear that your panel is fed with type SE-U cable, which has a concentric neutral, but no separate ground. The neutral bar would typically be bonded to the enclosure through a bonding screw, or strap.

But 35-40 years ago, many jurisdictions did not properly enforce the Code for proper bonding and grounding.

 

[kbsparky]

kbsparky....Could you explain concentric neutral just a little bit for me please?....

Here is a pic:

The neutral conductor is split into strands, and concentrically wrapped around the other conductors. Hence the term "concentric" neutral.