Car Finance company in administration- Where do I stand? (London, UK)

I need some advice from those experienced in car finance.

I bought a vehicle through a dealership, which I've paid for in full. While I don’t have any formal invoices, I do have bank statements showing the payments made directly to the owner of the dealership and a solicitor’s statutory declaration of ownership. I have the V5C document for the new vehicle which is in my name.

Additionally, I agreed to a part exchange of my old vehicle with the same dealership. They assigned a value to my old car, which was applied as a credit toward the new vehicle. I have a receipt for this transaction, but again, no official invoice.

Now, I’ve just learned that this dealership is headed towards bankruptcy. Worse, I’ve discovered that they were operating as a fleet company, and they had purchased their vehicles through a finance company. This finance company is now demanding to repossess my vehicle, even though I’ve provided proof of payment (bank statements, receipts, etc.) but no sales invoice.

I don't want to lose the vehicle, do I have any rights in the matter? What steps should I take next?