Hello Giorgio,
Please let me preface this with an acknowledgement that I am in no way an expert, nor do I have a collection the size of several of the more austere members of this site. Many others here may have very different insights on this subject than I do.
I can only give you speculation based on my experiences in seeing and handling helmets of this type which appeared to be as-issued. These observations have been generally concurred-with among a few collecting buddies of mine out in Southern California where I was stationed for most of my life.
The cockades on these types of helmets in as-issued appearance do always seem to have the pie shaped split from what I have seen.
The chinstrap on un-messed with, as-issued appearing helmets of this type seem to have always used small rivets rather than stitching at the buckles.
I have also seen examples of these helmets where the chinstrap and cockades have been replaced with standard ones as you would see on a typical M95. Both types of cockades and chinstrap fit both types of helmets and can be swapped, although the standard M1895 cockades do seem to rattle around a bit more loosely on this type of helmet.
I have made this assumption based off of these observations over time, and I have come to the PERSONAL conclusion that the chinstrap and cockades were proprietary to the manufacturer of these specific helmets when this company was filling this government contract.
If there are other points of view, observations, or if someone has contractual information concerning this subject, I would be very interested to hear it!
Bryan.