Dear Custard,
The requirement for no. 2 is contained in the "Guidance Notes," items 3 and 4, of the form whose URL I provided in my first message. These state that the certified CoR has to be submitted with the form. Presumably the CAA won't process it without the accompaniment.
Getting the full FAA PPL is indeed plan B. I've always thought it an unnecessary pain in the backside, though, to have to take out two separate licences because I want to fly aeroplanes in two different countries. My impression was that this sort of nonsense was precisely what the ICAO was invented to avoid.