@Stephen1120
When I started hosting Stephen, a wise man said to me..."Don't put anything out there in your listing you aren't prepared to lose"....and that is one of the best bits of advice I ever got.
Airbnb are not accepting host claims with welcome arms Stephen. The host guarantee is not an insurance policy, you don't pay a premium for it and there is not a defined set of circumstances under which you will be compensated. It is an adjudicated system, and obviously Airbnb want to limit their liability in any way they can.
I am sorry you are in this situation but Airbnb adhere to the letter of their claims procedure and if you miss any of their deadlines or requirements by even a second....you are dead meat, you have left them an out!
Take that 'favourite' piece of furniture out and do as @Fred13 suggests, put in something that you are prepared to lose!
Cheers........Rob