The Tamiya kits omit these covers. You can see a model of two of the three covers on this page . If you have an escape hatch on your turret, omit one cover because the hatch's hinge served the same purpose. The locking device for the gun was fixed to the turret roof with 8 bolts which sat in holes that penetrated the roof. Tamiya, seeing these bolts on drawings, have dutifully modelled the holes on the roof of their kits.
Some modellers go even further and add streaks of rust etc to the holes.
If you want realism, fill in these holes as if they never existed. The bolts had flat-headed conical tails which were countersunk precisely to the level of the roof. I've sat on a Tiger and looked for these holes and not been able to find them for a whole minute. This is 0.5mm short but looks OK to the naked eye. However there is a locking ring screwed on the gun behind the muzzle brake, and the kit represents this as a cylinder.