Only a guess, but the 3rd picture looks to be some sort of brake shoe mount. Did they have a mechanical way to stop the wheel rotation of the tail wheel? Most A/C with retractable undercarriage us hydrolic pressure to activate the main brakes during retraction, but the nose or tail wheel does not usually have a braking system installed. And they use e mechanical system that contacts the tire when it is retracted.
Other than that I am no help I hope others can help. Good luck!