About this detail of the Tiger
The Tiger's gun was nose-heavy and a large spring was used to balance it. The spring was inside a cylinder, mounted on a hinge within a trestle.
This photo shows that the top of the spring is a simple ball-and-socket joint in a steel cube welded into the roof corner. The top of the trestle can be seen behind the spring; it's bolted to the rear turret wall. The trestle appears to be too small in the Hachette kit. You could improve accuracy by building up the sides.
This is the cam, seen from the right-hand side. The chain can be seen, attaching it to the arm on the gun's recoil shield. I believe that the kit does not provide this arm.
Here are the spring and cam, seen from the front. The red paint is the original wartime colour. The object in the foreground is the commander's folding footrest.
The bottom of the trestle was fixed to the turret floor.