Thanks to a Mr Pierre Fontaine, Forgotten Trek presents two rare photographs of the Phase II bridge and engineering set under construction.

“The new bridge is four feet larger in diameter and has several doors that the old bridge did not have. The greatest change, however, is in its electronics. It is built into almost every square inch of the external framework, and when a crewmember presses a button it will actually perform a function. On the original set, the function had to be simulated by a technician offstage. The bridge has the same familiar circular look, though each of the stations is more clearly defined. In addition to the extra doors (including one which we must assume is a toilet), there is a large, transparent hemisphere (called a Weapons Defense Center Viewing Screen) which acts as a target mechanism for Chekhov when a combat situation is encountered. There is also two side consoles at the Science Officer's station which can pop out of the lower wall on either side to give him (or her, or it) additional control facilities.”
From Fantastic Films Magazine (August 1978)
Click here for the page with the larger view.
(Sorry I'm not including it in the post directly, but I don't like to waste lots of bandwidth.)

“The new bridge is four feet larger in diameter and has several doors that the old bridge did not have. The greatest change, however, is in its electronics. It is built into almost every square inch of the external framework, and when a crewmember presses a button it will actually perform a function. On the original set, the function had to be simulated by a technician offstage. The bridge has the same familiar circular look, though each of the stations is more clearly defined. In addition to the extra doors (including one which we must assume is a toilet), there is a large, transparent hemisphere (called a Weapons Defense Center Viewing Screen) which acts as a target mechanism for Chekhov when a combat situation is encountered. There is also two side consoles at the Science Officer's station which can pop out of the lower wall on either side to give him (or her, or it) additional control facilities.”
From Fantastic Films Magazine (August 1978)
Click here for the page with the larger view.
(Sorry I'm not including it in the post directly, but I don't like to waste lots of bandwidth.)