Then how can a plate contain 3 different numbers?

Given the style of CAAD's artworks, one could suggest that the numbers are just the colours he was tasting whilst he was painting them.

The 1908–1921 Books of Drawings

Aside from the memoirs, the only other works by Dellschau known to exist are the twelve hand-boundbooks of double-sided drawings that date between 1908 and 1921. For the most part they are vivid,colorful renderings of the airships and bear comparatively scant inscriptional detail; some works incor-porate press clippings and some don't include Aeros at all. Each drawing, which he sometimes labeled "Plate," is meticulously dated and sequentially numbered, beginning with 1601 and ending with 5235*. Sometimes he included the date on which a particular airship design was proposed to the Sonora AeroClub in the 1850s, as well as the name of the proposer. Characters introduced in the memoirs recur inthese later works. Because of the gap of eight years after the last pages of Erinnerungen, and because of the high number of the first known Plate, it is possible that Dellschau created approximately 1,600 drawings prior to 1908, but their whereabouts are unknown. Other gaps in the sequence appear in 1910,1913, and 1917.

As is characteristic of many self-taught artists, Dellschau did not operate in intermittent spurts but sustained a disciplined and regular output, numbering what he calls his Plates consecutively and signing and dating them with a keen sense of purpose. For long periods he was producing at the rate of a drawing every day or two.