Not just machine guns and petrol but the crew could be robbed too. A Junkers Ju 88 was shot down over Exeter during the war the crew bailing out at night. The pilot came down on his parachute and landed high up in a tree. He was dead. After hanging there all night a local boy having heard the stricken bomber crash during the night spotted him. He observed that the pilot was wearing a rather nice flying jacket. With no one about the boy shinned up the tree and removed the jacket from the pilot's corpse. The boy was twelve years old.
Alas the story did not have a happy ending for the lad. His friends jealous of his new jacket shopped him to the police who searched his home, found It, confiscated it and severely reprimanded the lad. You have to remember that these boys were from poor families and in wartime there were shortages of the most basic necessities including food.