One more thing about the later spec round foglamps/reversing lamps. I had a closer look this afternoon. As already mentioned above, they unscrew and the fixing is in the style of a jam jar top from the sixties. But there's also a cunning taper fit against the rubber housing which makes it tight.
I'd originally supposed that the blind rivets which are visible in the screw holes secured the lens to the metal bezel........
But no......
The lens is secured with what appears to be clear silicon sealer.
Those blind rivets are short (half inch) decorative pieces, and can be slid out, and replaced with decorative crosshead screws to match the other rear lamps. So being a bit anal, this is what I've now done.
