Salz as a celluloid pioneer

The question of who started making celluloid fountain pens, and when, is somewhat reminiscent of discussions of who discovered America. Sheaffer is the equivalent of Columbus here: others had done it before, but without any lasting effect.

Everyone knows that Leboeuf started using celluloid several years before Sheaffer, but other companies were using it by the second decade of the 20th century -- though as a substitute for black hard rubber, rather than for its potential for color.

Years ago I noticed that some of the earliest colorful celluloid pens were Salz Brothers ringtops, often marked "GERMANY" on their caps. I didn't have any way of dating them precisely, though, nor did I have access to any advertisements or catalogs that would help. But tonight I found this, in The American Stationer of March 11, 1922, p. 20:

By the later 1920s, the question wouldn't have needed to be asked; it is telling, though, that in 1922 such a pen would have required some effort to find, and that the one manufacturer that this major trade journal could identify was Salz.