Very nice, James. A model adopted in 1867; this one may have been worn during the Franco-Prussian war. Note "Meyer IV". Such a common German name there were three more in the squadron.
It reminds me that I need to strip that old gold paint off from the neusilber fittings on my helmet, something I meant to do last summer and did not accomplish. And to also work on my M15 Oldenburg Dragoon e.m. and remove the silver paint, and my M15 Saxon Garde Reiter using the evaporust product, now that it is finally nice outside to do this work outside the house.