"Weird (possibly rotating?) metal contraption found in a vacant lot outside Hamilton, Ontario"
A: "A “Swinging Gym”. You’d actually pay to get in one of these with a friend, and get it swinging with the aim of making full circles. A ton of effort and skill was required."
#4... What box? you see something I can't?
#2 Ive seen lots of adze, I live where they are made culturally. There are lots of different shapes depending on the purpose of it the region it was manufactured.