Frank, be careful with older information, because unfortunately a lot of incorrect information about the helmet has been published over the years, probably due to a lack of sources. This catalog was written in 1988, before the internet. The same Ulrich Schiers wrote in a later book "Mit Gott, für Fürst und Vaterland" ("With God, for Prince and Fatherland"), that the helmet was introduced in 1853. This also corresponds to my research, since I found a protocol from june 1850, from the Landtag Sachsen-Meiningen, in which it is written that the introduction of the helmet is coming:Sandy,
The helmet is said to have been introduced in 1846. See excerpt ‚ Ulrich Schiers, Katalog Nr. 5 Kopfbedeckungen, Museum Rastatt ‚!
Best regards
Frank