V627/1 Build up report is the one you want.
https://assets.publishing.service.go...7X1_270913.pdf
I add before and after photos of the car with the registration number visible.
I always include a covering letter explaining that I have added panels to change the appearance of the car but I have retained the identity of the original car as I have not modified the chassis / monocoque and that I require a change to the vehicle description only.