Hi Travensisember,
Those parts look good. Nice that you found a cheap 28 pin connector. I wanted to buy an aftermarket camera, so I went for a pre built adaptor, but if you are comfortable repinning the 28 pin connector, that should be a good solution. Going by my guide I left pin 1 empty, but it's a while now since I did it, so my memory is slightly foggy :) If you are having trouble when all the parts come I can try to take apart my dashboard again to have a look. I don't have any experience with the factory camera upgrade, but it's good you've found the cabling. Nice not to have to run that again. Where is the last picture taken? It could be helpful for other people adding the factory reverse camera kit.
Lastly, it looks like your original radio is different to my original radio. Mine didn't have DAB or the buttons along the bottom. Have you checked that it is a 20 pin connector? It's possible your radio doesn't have the same pinout as mine. If the colours are the same and they both of 20 and 8 pin connectors then you have the same pinout. If you are lucky, they changed to a 28 pin connector for your radio, and it will be plug and play :)