Basically, the VIS35 pistol (its official designation) was a Polish designed pistol, adopted in 1935. It was chambered for the 9 mm Luger cartridge and it featured a decocking lever - the first military pistol to have this device. The pistol was produced in the Government Arsenal located in Radom - hence the name.
Around 50 thousand had been made when the WWII started and Poland fell to the Germans.
The Germans captured the arsenal plant intact and quickly realized the gun potential. They restarted the production and kept it running until the end of the war, eventually moving the production to Steyr, Austria. Quality control drastically decreased during the war, which included finish change to phosphate and the supression of the take down lever. Total production during the war was around 320 thousand guns.
Hope it helps you.
Greetings
Douglas.