WW2 X-ray from Partisan hospital Franja

Hello I look for some information about xray from Partisan hospital Franja in Slovenia. Which was destroyed by floods in 2007 and then renewed. A larg collection of the medical devices from ww2 was destroyed one of them was also this xray. Information which i have about xray is just, that it was manufactured by Koch & Sterzel Dresden but can't found anything else about it. Here are some pictures of xray . I will appreciate any information. First picture was taken before floods and other are after the flood when the hospital was restored.