It looks like they bashed it and the control was sunken into the panel and wobbly.
On inspection, the two plastic lugs that seat in the metal bracket had broken off.
Here is my variation on a fix for the bender control.
Step 1: Open Up the Juno...
There is one screw at each end panel that you need to undo and remove and the top cover should then open up.
Step 2: Remove the Bender Control Panel
The panel should lift out with a gentle wiggle. Be careful here, there is a small lug on the right hand side of the panel that catches on the bottom key of the keyboard.
Inspect the mountings for the bender control. You may need to remove it. There are two screws holding the metal bracket in place.
Ideally the two legs of the bender seat in two plastic lugs on the metal bracket.
Mine were broken and too short...
The bender also has a 'push' movement that actuates a small switch on the back PCB. There is a wire spring that needs to locate in a tab at the top of the bender case. This is why the mounting needs to be free to allow motion sideways and the push motion.
Step 3: Make a Bracket to Retain the Bender...
So I found a small piece of 'L' angled aluminium about 10mm x 10mm, (although one side might be better a bit larger to allow the screws to hold it in place better than mine did) marked off where the screws should go and marked off a semicircle on the other edge to allow the bottom of the bender to seat nicely.
This worked reasonably well, but the bender was a little 'rattly' so I used some double sided foam tape cut into thin strips and laid about 3 layers underneath the bender and attaching to the bracket.
This fixed the wobble and provides a secure base for the control to sit on and also because the foam has a little give, allows the push motion.
This is my first instructable. I hope it will be useful to someone...