Japanese Coin, Button, Key Found at Home Sites

[MineEyes92]

Spent all day yesterday searching around a a couple of properties. One was a house built around 1910. Sadly, I only found typical USA modern coins for the most part, but I did find this Japanese 50 Yen piece, my first ever foreign coin! Did some research on the markings, and it looks like it's from 1974. I then went to another house dated to around the 1950s, but there are remnants of an older structure on the property. I'm uncertain of its age, but I did find this metal button and a key made by the Yale Company. I think might be old just but looking at them and doing some quick research online, but I'm not 100% sure. Really hoping I get another chance to explore this property. I'm sure there's more stuff to find. Please let me know what ya'll think of these finds! I'd love to learn more about them!