I am the cars previous owner and can confirm the information you have been told is correct. I had the same question when I bought the car but apparently some of the press cars had new manifold numbers assigned. On a visit to the classic motor show I had a chat with the guys on the FRP stand...
I had the same problem on my racing puma. It frustrated me for a while. First I changed the HCV with a genuine ford part. Great disappointment when this didn't work. I then went to the control panel and found the multi-plug wasn't connected, (I guess I should have checked that first), I...