also, be sure to take into account the "rouge ring" 6 1/2 : p. This was installed to be able to access the Blok D upper stage.
On top of the tower, from about 1985-2002, there was this "white room" for what I assume was the cancelled TKS program's cosmonauts to enter the capsule through. Exact specifications of this are unknown, since I couldn't find any documentation on it. although here are a few good reference photos:
A diagram of the various rings, 1 being the topmost, and 8 being the lowermost (the ring for the 1st stage not included) On ring "2", is where the cab would have been located, shown in red. "Ring 4" is where the Rouge Ring 6 1/2 is.
This second view, shows the position of the "white room" cabin.
This view shows the Proton K carrying Zarya on the pad, shrouded by the Service Tower. The red shows the TKS "white room"/Boarding cabin, while the blue circle shows the "Rouge Ring 6 1/2".