Thank you for posting this image Mr.Mosher, so if indeed it was the COs tunic, he most likely would have had this sort of collar insignia. So most likely, it is safe to assume, the tunic I have did not belong to the CO, but someone else, someone who would have had the Gallipoli star and the Johannater Order.
As per the photo which member GreyC posted above, the officer is wearing both collar litzen and cuff litzen. On my tunic, there is no cuff litzen, and the collar litzen appear to be a generic officer variety, as you kindly mentioned were M-1915. My question was if my tunic is indeed correct being in its configuration, or if it should be like the one in the photo which GreyC posted?