About this detail of the Tiger
All Tigers built before late 1943 had two boxes, inside the turret, dedicated to storing spare vision blocks. In "Initial" Tigers, these boxes were always in the same place; high up on the wall behind the commander.
These are the boxes in the surviving Tiger "712". One of them has lost its locking bar, but they are otherwise intact. Note that they are mounted on brackets (arrowed) that hold them out quite a distance from the wall.
This diagram shows the dimensions of the boxes and the brackets. We also have full information about placement of the vision block boxes.
This model kit uses parts J82 and J83 for the boxes. But it does not provide the brackets that hold them. The parts are inherited from the kit "Eastern Front Tiger" which didn't need any brackets.