The 2nd Polish Corps took part in the Italian campaign,at its peak it numbered 102,000 men & women,its equipment & supplies were provided from British stocks,including its motorcycles,below is a Triumph 3HW at the Brigade signal office at Senigallia. 
No location for this G3L in use by 2nd Polish Corps despatch rider. 
Here's some I have....Not much Info as they were posted on Ebay and just said Polish Italy.
BSA M20 2nd Polish Corps Italy,with what looks like white front tyre wall. 