My late friend won his appeal, I took him straight to our Ford dealer with his appeal paperwork showing the award and they had no problem placing the order.
Motability were very helpful. He got the DWP award letter about a week later but that was pre-Covid so timescales may be different now.
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!