Here's the reverse of the 17th SS tab. Note how blood ate away material, as well as part of the paper RZM tag. The acidic qualities of human blood are considerable, if not cleaned-off. I have also seen pitting on souvenir Luger pistols, caused by blood traces, which were not cleaned-off the surface of the metal. This was first pointed-out to me by a 9th Infantry Division vet, who had an otherwise pristine Luger from a Luftwaffe officer, whom he shot while the officer was holding and firing the pistol. I observed that pitted piece around 1970, as the vet told me the story and pointed-out the blood-induced pitting.
