Hi Hela and Cwaver,
I have uploaded a similar photo of a Polish Army NCO officers uniform.
http://gmic.co.uk/index.php/gallery/image/9605-military-school-poland/
Unfortunately, my father's photo has been cut but you can see the design of the uniform. He was also stationed in or around Lwow. I believe he was in the cavalry but then got transferred before they were ordered to attack German tanks! He went on to North Africa (Tobruk, El-Alamein) and Italy (Monte Casino) with the Polish 2nd Battalion in the British 8th Army.
Best wishes, Jansos