About this detail of the Tiger
The Tiger 1 had a gun mantlet in the form of a horizontal cylinder attached to a flat plate. The cylinder, of 390mm radius, was mounted within the turret front armour.
This partially complete model illustrates what the metal bars looked like in an "early" turret. There were in fact 3 bars, of 470mm length. They were held in place by countersunk hex-head bolts.
The Tiger's turret was redesigned and significantly simplified at one point. One of the changes was to stop making turret frontal armour with a curved profile. On the right hand side of the diagram above, you will see how the "mid" and "late" turrets were shaped; the sides of the opening are flat, providing no splash protection. Instead there are two identical sets of metal bars, above and below. In the diagram, I have removed the lower bars to show the notch where they sat.
These photos of the surviving vehicle at Vimoutiers show the splash guards above and below the mantlet. You can see that the upper one is quite prominent and should be represented on 35th scale models. Unfortunately, even the newest Tamiya kits have a mantlet whose diameter is too large, making rework difficult.