Join Date: Aug 2010
Location: Fort Frances, ON, CA
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Top picture: Bottom right appears to have a little nubbin (technical term meaning thingy) that you'd pull out to release the top cover to swing away from you like a laptop screen.
Third picture: That hinge is for the "sight" to pivot up on.
The reason you can't see the W, S, E marks is because they are on a fixed plate that swings with the device, and there is a needle/arrow that indicates the direction being sighted.
They used similar devices in fire towers.