HELP! What the heck is this?

Hey Scamp. I have that same part underdash on my 74 Dart. It is not a relay. I can't find a part number in my FSM or in the 74 Chrysler Parts Catalog. I'll keep looking and get back to this post. In my opinion there are too many wires running into this box to pull it.

In your first picture at the 3:00, 6:00, and 9:00 positions there should be a plastic cover in those tabs. Do you have the cover?