In the mid-60s when I visited the 72nd Street yard -- which officially was the 60th Street yard -- the enginehouse and adjoining turntable were about a city block south of W.72d Street. They were located on the river side of the yard, under the West Side Highway viaduct. I believe getting a unit into the house required the use of the turntable but I could be wrong about that.The enginehouse was rectangular and looked only big enough to house one unit. Former NYC employees told me that by the 60s Central probably only used it for running repairs and inspections on the yard engines. If a road unit needed some quick work it was probably done on the ready tracks or the unit was sent dead-in-tow to Selkirk.
The signal tower / yard office DO was flush up against 72nd Street but just a bit lower than sidewalk level. You could look into the office area from the sidewalk. In fact if I remember right, employees could exit directly onto the sidewalk. It always looked like a small airport control tower to me.
There aren't many NY Central era photos of the yard that I have seen. A few in one of the Nowak books are the only ones I know of. Too bad because it could be a very interesting and busy place.
When I visited 72nd Street I was junior high school age and not really into photography yet. I was happy just to watch.