On the turret roof of the Tiger, just in front of the fan, there were 8 small indentations. They are shown in this photo.
They were the ends of the fish-tail bolts of the travel lock for the gun. This diagram shows one of them protruding through the roof.
The lock was mounted under the turret roof and could fold away when not needed. This photo shows the lock from the inside, located just ahead of the opening for the fan. (The green paint is not original.)