About this detail of the Tiger
There were detail changes to the turret during all of the Tiger's production run, but a very significant event occurred in 1943 when the cupola was changed; the turret was so extensively redesigned that it got a new manufacturing part number. When I refer to early and late turrets, it is this point in time that I mean.
A curved piece of armour was welded underneath the turret chin, and the side walls were cut away to accomodate it. This was done differently in the two turret versions.
The early model is on the left of this diagram, and the late model is on the right. The late-model turret was simpler to manufacture, as the following diagram suggests.
In the early turret, a curved chin piece sat into a notch in the armour. In the later model, on the right, you can see that there was no notch but they angled the end of the armour to hold the chin piece more firmly.
This diagram profiles the curved chin piece. The turret's central axis is at the left. In the early model, at the bottom of the diagram, the piece has a complex shape. The late version is simpler to manufacture.
The models above show the chin piece and armour for both the early and late version turrets. There were two slots for the turret travel lock cut into the early version.
[1] Factory drawing 2AKF31861U1B12: Turmgehause (turret front plates)