On any day other than the one I found an Eisenstadt pencil, today's subject would have been the headline, rather than the "other" pencil.
The Nardi was a fascinating little design, concocted by Romolo Nardi and patented by three distinct patents beginning in 1923 and with the latest in 1926 (see page 104 in The Catalogue for more information). Only Nardi's third design appears to have been produced.
The first thing that is striking about this example is the spectacular color. Most of the time, Nardis are found in solid colors, although in a wider range of color than most mid-1920s makers. Prior to this one, I've found only one other in a color that wasn't a solid color, but it was along the lines of a Diamond Point plastic (compare to the Diamond Point on the cover of The Catalogue).
This plastic appears to be much later, from the 1940s, and matches plastics used on several second and third tier brands: compare this color to that on the Ambassador at right in frame 4, page 85 of The Catalogue, as well as the National on page 153.
There are other differences. Compare the new addition with the ones already shown in The Catalogue:
I've placed these in the order in which the design appears to have progressed. Note that the top on the first two is hard rubber, on the second two is brass, and on the new example is nickel plated. There also was a transition in the ball clips between the red example and the pink one - see how the clip is flatter and the lettering is larger?
But the clip on this new example is a different animal completely, abandoning the ball clip entirely for a unique design:
The only patented Nardi design that included a clip showed the ball clip matching the earlier examples. When and why the design was changed is still unknown. However, between the clip and the plastic, it seems clear now that the Nardi was not a short-lived production as I had previously thought.