I don't know the answers for the first two, but I think that I know the purpose of #24 & 25:
- 3-1/2" long, someone found this underground in their garden: formatting link
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- The owner's description: It opens and closes and it has an attached brass square that flips down.It has two brass squares that are not attached.It is marked Made in Germany so it predates WWII.only about 1/8" thick.The one square that is permanently attached folds down in either direction to "prop it up", I don't know if that is it's primary function though.It has 2 brass squares not attached, A SOLID RECTANGLE AND A "FRAME TYPE RECTANGLE brass plate dimensions -The larger two are exactly 36mm x 25mm.The one that is connected is 28mm x 21mm. formatting linkformatting link
- 8" diameter: formatting link