One of our oldest living Gun Club Members is a WWII combat veteran from the Pacific. He was a veteran of Okinawa and Iwo Jima. He was in the occupying force post war Nagasaki and said walking across the ground was like walking on breaking glass.
When he returned to the US in a troop ship, to San Pedro Harbor, all enlisted men were required to open their duffle bags for inspection. Those with Japanese rifles were required to get in a line and have the crest ground off, in America by Americans. He said he was told it was because of an agreement we had with the Japanese Emperor. He said there was a pile of grenades, mortars, and land mines which had been confiscated from returning GI’s!
He did not bring back any US service arms and I have no doubt those would have been taken from him.