It was immediately coined "Chanel's Model T," after Henry Ford's "car for the multitudes" made (in black) from 1908 to 1927. I daresay an original Chanel dress and a Model T cost about the same!
Waterman Pen Company may have been influenced by both Chanel and Ford when they offered their Patrician and and Lady Patricia pen and pencil lines. They offered both in "Jet" with chromium trim.
The ad for the Lady Patricia pen states,"Lady Patricia is designed expressly for the woman who demands not only a perfect writing instrument but one attractive enough to be used as an accessory for her handbag. It embodies many features dear to the feminine heart--dainty, jewel-like design--slender grip--and a chic, modern clasp that secures Lady Patricia conveniently upright in even a crowded bag. The polished disc on top of cap offers an ideal place for engraving." The matching pencil looked like this.
It is 4 & 1/4 inches with 1.1 mm lead and an eraser under the top cap. The top's "polished disc" is indeed plain and the clip (clasp, in the ad) and band have a subtle design.
This twist pencil has a Waterman imprint on the back of the cap which says "Waterman's, Reg US Pat Off, Made in USA."
If you'd like to see the onyx Lady Patricia, it is in the final photo of this blog: Made for Each Other