This plunger in the hull roof is what locked the "early" Tiger turrets (for travel etc).
The original plunger was a plain cylinder and the turret had three round holes in its bottom edge, allowing three locked positions. But later, the plunger was tapered (as shown in the model above) and the turret holes were replaced by slots (easier to manufacture). The two slots at the front of the turret were covered by welded steel rectangles.
This photo compares the real slots to Takom's model. Takom have made the protective rectangles much too thin, and they seem to be oversized in the vertical direction.
It's also obvious that Takom's weld line is about twice as thick as the real one.