I should have explained where I get these statements, but I was worried that a too technical post might not be interesting.
Firstly, let's point out that Doyle and Jentz are famous for not using anything but original materials. These gentlemen spend years researching for their works and they are very professional about it. They don't speculate or repeat secondary information.
They state that the heater port was introduced in February 1944, and we can assume they found this data in the German archives.
Now, to the photo. This annotated copy, and everything I will now tell you, is due to Bary Crook.
The heater port is pretty clear to see. Compare to this photo of it:
But there is much more evidence. When the port was added to the tank, the ordinary Tigers were OK but it collided with the antenna storage tube on the command Tigers. Therefore the layout of tools on the
entire back wall was 'mirrored'; the antenna tube moved from left to right, etc.
This tank has been 'mirrored'. All of the tool storage is visible in the photo. That is the irrevocable proof that it really has the heater port, and therefore was made in or after February, and therefore cannot have been present in January.
The unit may have had a command tank numbered '007' in January; it just wasn't this one. Renumbering of tanks was not an unusual event when units were reorganised. A large delivery of new tanks might be the reason for a reorganisation.
Now, as for the other claims that you dispute:
Turret protector ring: look at the hinge of the turret escape hatch. It has 2 bolts and 1 empty hole. The hinge had 3 bolts until the protector ring was introduced; then the existing hinges were partially cut away, leaving this empty hole, while a new hinges were made with 2 bolts only.
Rear travel lock: while it's possible to unbolt and remove this, it leaves 2 prominent welded supports which are not in the photo.
David