I have just had one of those moments where you realise ignorance has caused you to miss something really obvious...
In my previous post I described how I slowly came to realise my Austrian grandfather had served with a battalion, not in upper Austria, but in Galicia, or what is now western Ukraine. This was triggered by the photograph I have inherited of him in his pre-WW1 uniform and help I received in identifying his battalion.

When I looked again today at the photograph of him in his pre-war army uniform I noticed the word 'Lwow' in large letters underneath. I had always ignored this word, thinking it was merely the name of the photographic printing company. But of course Lwow is a city in western Ukraine - present day Lviv. He would have had his photo taken in uniform locally. This was him IN Lwow. His battalion was based in Lemberg between 1908 and 1911 - the German name for Lwow, present day Lviv.
Given that my grandfather was born in 1891, does that mean he must have been between the ages of 17 and 20 in this photograph? To me, this looks like an older man? The battalion was based in Steyr between 1912 and 1914, not that far away, so there is the possibility the photo was taken in Lwow sometime during these years?
But in terms of a glaringly obvious clue about the Ukraine, this clue had been staring me in the face all along.