Many cars have chrome/polished stainless trim rings that go around the
headlights. I have a set of these brand new in the Lucas box, but all
that I know about them is that they are not correct for my Sunbeam -
they were in a box of spare parts that came with the car when I bought
it. If I can figure out what car they fit, I'll sell them to somebody
who can use them. The part number is 555457. Can anyone cross this
number and tell me what cars it is correct for?

Mike wrote:

The diameter of the inner hole varies in size The aperture which the
headlamp passes remains the same.

whats the diameter of the rim at the car body side?

They fit a variety of cars. The attachment screw or clip is changeable.