My Main Man and I worked all over the world. We are both retired from a large government agency. My pal told me a few years ago that he was with his uncle who just had days left to live. He knew that my pal was involved in some career in which he lived in the shadows. His uncle finally “came clean.” The uncle was a classical musician who had worked and studied in Italy in the 1930s, during which time he became fluent in Italian. Once back in the US after the outbreak of hostilities, he was approached by the OSS. So the uncle underwent months of training and parachuted into Italy where he organized partisans to sabotage German operations there.
I also find it hard to believe anyone familiar with weapons would say “millimeter caliber”.