After a considerable ammount of fettling I finally have an acceptable radiator surround.
It was orginally fitted very badly and I struggled to get a better fit until I finally discovered the whole moulding is on the sqiff! Once I had worked that out I managed to get a reasonable fit although still not 100% square at least it looks OK to the eye. In the process I filled many holes and extended the sides down so they touch the chassis rails. Needed as I will be using cycle wings so this part will be visible. I also did a bit of re-inforcing arround the edges and filled in the gap that is normally visible between the front horizontal edge and the bumper. (Later cars have a neater wrap arround bit that fitted arround the bumper and provides somewhere to mount the number plate.)
rad_surround by
Robin Martin, on Flickr