Hello,
I don't think the fact that the cockades are missing has anything to do with the type of helmet cover for the M15 model. This type of helmet cover consisted of two parts: a shell cover and a spikecover. Very often, the peak cover got lost...
View attachment 79634
View attachment 79635
Before the M15 Pickelhaube and Überzug were introduced, as we can sometimes see on period picts, it was very common that soldiers began removing the fixed tip from their M95 helmets, taking off the entire base of the tip, but very often also cutting off the tip just above the round base. They did the same with the helmet covers, simply cutting off the spike cover and then by tightening the top of the helmet cover with a makeshift string
Here a helmet + Überzug first worn in the JR173 (one can see the ghost of the old numbers"173" on the Überzug that have been unstitched), completely cut off after a few weeks of war of position, and later moved to the RJR73.
View attachment 79636
View attachment 79637
View attachment 79641
View attachment 79638
View attachment 79639
View attachment 79642
View attachment 79640
View attachment 79643
View attachment 79644
Philippe