Those "Larisch Stickerei" (there's no "alt" ['old'] are known as well as "Alt-Preussische Stickerei".
The very first time these "Stickereien" were used, was with the [Prussian] 26th Infantry Regiment, one of the "old Prussian" regiments.
The last commander was Major General (later General-lieutenant) Carl Leopold v. Larisch. Since regiments were named after their commanding officers - the 'Kragenspiegel' (this term is only used after 1945) was named 'Larisch'.
It was used in this regiment since 1714 as a rank-sign for officers. (The regiment was dissolved in 1806 - part of it was transferred to the III: Corps, the reservist joined the 1rst West Prussian Regiment.
Oak tree leaves.
That it looks like a tree is ... coincidence.
It changed during the years, since it really was 'manfactured' (=handmade)
What I have found suggests the original was a unit badge.
As such it would have been stamped metal, but you are right that once the tailors got in the act it could change considerably.
So Walt, where is the answer to the original two questions ?
You say it has changed but what was the original basis for its design ? I have found some similarity to the Larisch coat of arms at the time... did it come from there ? I am trying to find the original badge (26 Infantry Regt circa 1740) it may have derived from... can you help ?
the original basis for the 'Kragenspiegel' of the Prussian 26th Regiment was done during the period of the commanding officer von Kleist.
Most of Infantry Regiment Nr. 26 surrendered at Erfurt. Some sources state that the unit was attached to Ruchel’s corps.
I have found a uniform from Frederick the Greats time and the device seems to come from LAPEL button holes, not a unit badge . The end part that looks like the tail of a comet is actually a tassel on the outboard end of the button loop . The extended oval shape in the middle is the button hole . The shape coming out of the top and bottom of the button hole is not yet 100 % identifiable (yet). None of the uniforms I have found so far have anything that looks like a leaf at this early stage so it may be a later invention.
The whole device is part of the decoration of button holes that only officers wore. The original seems to be more of the knot that appeared on shoulders rather than the oak leave appearance it has later. Still working....