Reverse camera doesn't pop out, but sends image ok

[DoItYourself]

Hi folks,

Got a RCD330 HU with OEM emblem camera in a 2009 Golf MK6. Camera is connected via a RGB->AV converter.

When putting her into reverse, the HU shows the camera image with 2x yellow lines overlaid on a black screen. Initially I thought perhaps the whole emblem camera & mechanism was dead. However, if I wedged open the handle a little, and pry open the camera "trapdoor" - then the housing is slightly illuminated and this shows up on the HU. If I shine a torch in there this is clearly visible on HU and it's clear the camera is functioning fine - it's just the mechanism which isn't budging.

With the car on and in reverse I've checked the 4B0973712 4-pin connector at the badge/camera and I'm getting:
12v to pin 4 (constant power supply)
12v to pin 3 (reverse signal)

Any ideas as to anything else to check?
Note: I have not changed any of the VCDS coding - is this required to make it work with RCD330?

A little history...
Car initially had a RNS510 with the OEM emblem camera and all worked fine.
At some point the camera image would only display sometimes and eventually not at all, but the badge always popped out.
Sold the RNS510 and replaced with RCD330. We connected up the camera, albeit probably incorrectly because the 330 never detected it and gave the usual error. So lived without the camera.
Later the camera got "stuck" in the open position. Couldn't open the boot via the handle because of this. At this point I decided to remove the entire badge/camera assembly to troubleshoot. I found the infamous snapped wire (red or yellow) at the camera body and repaired as best I could. Also removed the motor and cleaned & lubricated moving parts with silicon paste. I was also able to get it back to "closed" position too. Once re-installed the boot latch worked again, i.e. could lift and it would release the boot. But it seems the mechanism no longer pops out the camera when put into reverse.

This is where we are now. I thought perhaps the camera needed to be connected to the HU for it to pop out. It's first time the camera has been "correctly" hooked up to the RCD330, as we've never had an image displayed without error. Now only the stuck mechanism!

Anyone got any recommendations or know of anyone that might repair such things? It seems such a waste to pay $700 for a brand new one, or $200 for an aftermarket one - then have to run new wires (argh)

Any help much appreciated!

I'm in Melbourne SE suburbs.