Hello Ced,
In my opinion that appears to be an Austrio-Hungarian (KuK) fireman's helmet but it is heavily modified. One of the indicators of that is the metal bead above the helmet brow as it meets the body. I have never seen a dragon on a KuK helmet comb before, so that has me stumped.
The coat of arms looks like that of Montenegro.
I am positive though that this is not an issued dragoneer helmet of any of the KuK armies.
John