I wish to thank everyone who participated in this thread. I have to admit that this went on longer than I expected, but I received several additional avenues for research from everyone's comments.
Some additional discoveries:
1) The Kokarde, credited to the French, was used by several of the 39 independent German speaking states prior to 1808. Bavaria began using a white-blue-white Kokarde in 1806. Bavaria fought for the French. The Kokarde was not adopted by Prussia until 23 October 1808 and it initially had nothing to do with rank. It was a symbol for national unity and national pride. Prussian Kokarden were black-white-black since their inception, but the style was varied and largely based upon the Regimental Commander's desires. The Kokarde was primarily used only by the military at this time and it took time to phase it in between all units. The infantry, Jagers, and Landwehr still used a Feldzeichen on their bell top shakos. All Kokardes were silk. Wool was not adopted for the Kokarde until 1813 and was phased in between 1813 and 1816, primarily to save money. Officer Kokarden were the same as enlisted; however, sometimes officers would have silver thread sewn into the white area. The Prussian Kokarde was standardized by Friedrich Wilhelm III on 22 February 1813 (one month before declaring war on France in the War of Liberation) and was mandated to be worn by all men 20 years old and older. It was to be worn on their hats. Women were not allowed to wear the Kokarde. Anyone refusing military service or showed "cowardice before the enemy" was denied the right to wear the Kokarde. Reaction to this order was said to be "extremely enthusiastic".
2) Officer uniforms did not differ much from enlisted uniforms except that officers had to pay for theirs. This may explain the continued use of the tricorn by officers since this "new" helmet could not have been cheap, even then. Officers were given a great deal of latitude on their uniforms. Uniformity was at the discretion of the Regimental Commander. Numerous references cite instances where regimental commanders placed "undue hardship" on their troops and junior officers by requiring additional uniform items. This was especially common in French regiments. One reference from the period cites that a regimental commander demanded all uniforms be the same color so troops showed up for parade with "paint still dripping" from their uniforms. Enlisted uniforms were considered livery denoting a subservient position of enlisted to officers. The Portapee and the epaulet distinguished the officer ranks, not the Kokarde. The Portapee was the only officer designation until 1806.
3) The parade plume used on the M1809 was simply a bunch of horsehair tied at one end and stuck into the front Raupe support of the helmet. It was used for parades only. It became a "fashion statement" or, we could say, en vogue, so it's popularity made it standard on 22 January 1810. Because the removable plume would fall out it became a permanent part of the helmet starting in 1810. More horsehair was simply sewn into the front of the Raupe.
4) One reference stated that "officers wore a queue and enlisted men wore a clubb". I had no idea what this meant, so I did an internet search and found this link:
https://www.nwta.com/courier/6-96/hair.html" onclick="window.open(this.href);return false;
Very interesting --- if you're into period haircuts!
Thank you all again for your input.
John