Update on the status of my claims:
1. I've had my £520 compensation paid and my expenses paid (received on 26 Jan).
2. I've had the principle of my downgrade accepted, and it's been passed to a fares team to calculate the compensation due. It's been a good 3 weeks since that happened, so time to chase them on that one.
3. I've also had my request for ORC passed to another team as well, but heard nothing back from them for 3 weeks either. So will need to chase them as well.
I'm happy to share any documentation I submitted if anyone thinks it might help.