Lion and Temeraire were laid down; Thunderer and Conqueror were never even started.
This, I think should be the limit of where we can build "semi-true" designs. I regard the Montanas, Lions, and H-Classes as ships that might have been built if Midway never happened and the war dragged on into the late 40's.
We HAVE to have these in, though - Britain needs more big BBs for me to sink, and to drive...not to mention the coolest name (Thunderer) ever imagined for a battleship