I wrote about it here: Moore Mastercraft
During the war in the early and mid-1940s, the Mastercraft pencil was still being produced. Its celluloid was still very nice, with marble, patterned marble, solid colors, and the striated pattern. However, the bands and clips were simpler and more inclined to show wear, and the rivet holding the clip was smooth rather than tooled. Here is a war-time Mastercraft.
As before, the clip's "Moore" with interlocking Os is the only marking. The standard size was like this one, 4 & 7/8 inches, with 0.9 mm lead, and middle twist mechanism. The decoration on the clip is a precursor to the next Moore design, the Fingertip.