Electrical Bulkhead Connector?

Here's a pic I find on the interweb. You can see the "ears" sticking upward on the 3 connectors.

Like crackedback said, use a small screwdriver to "gently" pry the tabs from the bulkhead. After 50 years they can become brittle and break...or they can bend and not return!

Search around the boards for more info on cleaning them up and using dielectric when putting it back together.