I'd love to know more about these.  All that I have found are repeater-style pencils (the one example shown is missing its top button), made to look more than a little like Eversharp Doric repeater pencils.  Many have clips that are marked Sterling.  Quality is generally not too bad, although I don't understand why you'd put a sterling silver clip on a pencil with a black plastic tip and top button.

The clip on the example on the right strongly resembles a Penman, but the clip may have been licensed or outsourced.

Note the similarity between these examples and the Whitlock.