Photo of a British Battlecruiser (tentatively labelled GB/CB/1907)

I have this drawing from 1971 of a British battlecruiser with 8-12in and 12-6in guns. The ship was large, with a 600ft length and a normal displacement perhaps of 21,500 tons. The protection was 6,678 tons. The normal maximum speed was 28.6 knots and the maximum overload would be 30 knots. The normal SHP was hoped to be 80,600. This is the photo of this design: