About this detail of the Tiger
The Hachette Tiger kit includes the recoil guard, a metal frame that extended out behind the gun. When the gun fired, it recoiled for a considerable distance, the force being absorbed by a hydraulic buffer. If this were ever to fail, the recoil guard would catch the gun before it did damage to the turret ring.
This blog photo shows the kit's assembled gun. The green part is the breech, which recoils towards the upper left of the photo. The recoil guard frame stands ready to catch it. The frame also supports a canvas bag that catches used shell casings.
Here is the recoil guard in a real Tiger (the green paint is not original). At the left, you can see a rounded metal panel; this was actually the back of a thick leather pad, which is missing. The misfired breech would slam into this pad. At the right, you can see some of the tank's original ivory paint.
Comparing this to the Hachette kit, you will see that they have left the side of the frame open, when it was in fact closed by a panel. You can improve your kit's accuracy by adding this panel.
This is a better view of the side panel. It bears a simple sliding indicator that shows how far the breech recoiled when it was last fired. The words 'braun ark' remind us what kind of hydraulic fluid to refill the buffer with.
You could make your Hachette kit even more accurate by adding the recoil indicator.