Sorry, I didn't look at the pictures all that closely, I was reacting to the text and misinterpreted what you were describing. The connector circled below goes to the switches and volume control on a small PCB in the tender shell. There's a harness that comes down and connects to this connector so you can separate the shell from the tender frame.
If you're missing that PCB and harness, you'll have to trace it out and wire something up for the switches and pot.
