I think you are mistaken re the number mounting. I went back through my pictures from MOG2011 and found a picture of the car in the Concours.
The number is mounted using the standard wing stay. The flattening you observed is most likely Pickersleigh Rd generated.
![[Linked Image]](https://www.tm-img.com/images/2026/01/11/IMG_3970.jpg)
Here is a cropped image ( a bit fuzzy but it helps)