Originally Posted by
John E
Is that green one designed to work in both left-side and right-side drive markets? I have never seen headlamp bosses on both sides of the fork before. Useful for visits to the continent?

I've seen numerous frames with twin mounts and at least one period photograph of someone using dual headlights. I think it's mostly useful for seeing things in the dark, period.
Virtually all of these Carlton frames, as with most high-end British frames of the period, were ordered to individual customer specifications. If you see two mounts it means a specific someone wanted two mounts for their own purposes.
-Gregory