Liddell's 1925 patent design for Moore was robust, reliable and attractive - so it's no surprise that the company kept the series in production into the early 1930s. But after Sheaffer launched the streamlined Balance series in 1929, boxy flattops became obsolete practically overnight and Moore, like all other manufacturers, suddenly felt the pressure to modernize its product line.
Moore responded with pencils that were more conventionally designed than the Liddell patent examples. Here's a picture of some, taken from page 101 of The Catalogue:
However, for the time being, Moore retained one of the most distinctive features on its pencils, the "Moore clip," which was unique in its looped over design.
Note that green and bronze example fifth from left. It's made from the same plastic as Eversharp's "brazilian green" pencils from the same period. In addition to having only one center band, this one is different from all the other pencils shown in this picture in one other important respect:
It is completely unmarked.
There's no question it belongs with the others in the photo, since it does have a Moore clip and to my knowledge no other manufacturers pilfered it. A while ago I ran across another example, which when shown next to it tells me a little bit "moore" (pun intended) about these:
The cream-and-oxblood color is common, but is definitely not a Moore-ish color, just like our brazilian green example. Although the clip is also unmarked, the cream example has a double band and a Moore imprint on the back side of the upper barrel.
Why? I don't know.