Hello,
The Hessian ‘troop’ helmet is very atypical compared to Prussian standards. The Hessian ‘officer’ helmet is too!!!
To analyse and identify this helmet, it is necessary to proceed meticulously, analysing every detail:
The tip:
---It varies depending on the regiment:
***Fixed single piece 116R, 118R and 168R. ( No Busch).

***Screw-on fluted tip only, in nickel silver 115R, in brass and 117R. (for Busch)

***Fluted tip with skirt (like Prussian bayonets) in nickel silver DR23 and 24, in brass TB18. (for Busch).
Here, it is the third case. We know that fixed spikes are for regiments that do not have Haarbusch, in parade. But for practical reasons of transport, many regimental officer helmets without Busch had removable spikes, especially during the fashion for high spikes just before the war.
Therefore, this officer's sword tip can identify:
---In theory, a TB18 officer, and by default 116, 118, 168JR, if we disregard this ‘gilded brass’ tip.
---In theory, a 23 and 24 DR officer if we take into account this ‘silver-plated nickel silver’ tip. (We exclude the 115 Leib-R officer, who would not have this skirt.
The lion on the front plate:
---If gold: 116, 118, 168JR and TB18. (We exclude 117R, which had vintage banners).
---If silver: 23 and 24 DR, (we exclude 115R, which had a different plate with double laurel and oak on each side).
The Land-cockade:
This cockade is an Unteroffizier-Portepee cockade, not an officer's cockade. An officer's cockade was ‘ribboned’. This is not normal.
The scaled chin strap:
***In theory, for all Reich peaked helmets:
---Infantry, Pioneer, foot troops, heavy artillery, siege and fortress artillery, artillery and foot:
flat scales.
---Train, all mounted units (FAR, UR, HR, JzPf, KR, etc.):
domed scales.
***But once again, the Hessians are unique.
Since 1897, only officers of the 115R were required to wear flat epaulettes as per regulations. In practice, many also wore curved epaulettes, as in other Hessian regiments. So here too, there is an anomaly.
***
Other distinctive features for Hessian officers.
---Round visor, including for Dragoons. (same as troops).
---Cruciform spike base, including for infantry and artillery. (same as troops).
---No pearl ring.
---No stars (except for the three regiments bearing the star of Louis the Lion).
---Two rivets securing the rear spine (as on Prussian Dragoon ‘troop’ helmets) regardless of regiment, even for foot soldiers.
To be continued with conclusions on this headset.