Mapping

My husband and a friend went to the national geographic place in London last night for a lecture and exhibition on cartography.
This is my fathers map from WW2. He was in the royal engineer Corp ( I think) doing communications. He was stationed in India and served in Burma. He was given this map of Burma in case he got lost. One side is north Burma and the reverse side is south Burma . The maps were silkbe amuse they were light and easy to carry but most of all they did not make a noise, ie rustle when opened . They didn’t fall apart if they got wet either. This particular one was made in America. There are a couple more views in extras