I may have one or two. I tend to remove a bit of the chrome plating and solder the insert on to the backplate to prevent them falling out.
The ones sold by SVC have metric threads and the original Lucas are either 4BA or 6BA and the screws correspondingly different if this bothers you. I have re-tapped them to the BA thread to match the threads on the side/indicator/reversing lights on rest of the car. Usefully, the metric thread is smaller than the BA one so re-tapping is ok and provides a good thread.
