Used to see one of those things in almost every modern Russian towed artillery unit stationed in East Germany back in the day. Sole purpose was to perform the close-in anti-tank defense role which would have given the gun crews time to retrain their weapons to address the new close in threat. Always stood out in the crowd of other gun tubes and easy to recognize on aerial imagery from the Berlin Air Corridors :)
Looks like you have captured the action quite well. Great work!