I would assume by 1953 there wasn't but I do believe there is some fact to what he is saying  battleships during the war experimented with different styles of torpedo protection and armor belts which they did try to keep on a need to know basis, early torpedos hit the side of a ship and detonated or at least tried to the success of early war torpedos had a dud ratio of something like 1 out of 3 and the ones that did find there target weren't that successful unless they hit specific areas of the ship, later war torpedos were more successful but still not great against armored ships but we're good against ships like cargo haulers troop transport and merchant vessels.

Battle ships had torpedo belts called blisters a voided space over the inner hull so side hull hit would hopefully not penetrate which lead to developing torpedos that exploded under the keel of a ship causing maximum damage.

So hiding the details of the hull structure and propulsion system would be a goal. A good example of this in current times is the screw of modern subs which is always covered when in port at times were the sub is sitting for a long enough period of time for a satellite photo to. Be taken.

Idk if this all applies to the model kit in the 50s but that might be partial truth to the situation