RE: what are these
Here is a photo of Tamiya's Static Tiger. It includes the hinges, latch, and periscope. If the hatch can be separated from the hull, you could add these. I have a Full Option Tiger, and since the hatches are separate parts, it was easy to add them. The kit has been discontinued, but parts are still available. What you would look for is Item #36203 1/16 German Tiger Early Prod. The 'K' sprue that you need.