The new wye connection at BO was put in about 1970, along with the new connection from the LSMS at Michigan Ave over to the CK&S (the stub of which is now know as the junkyard spur). The switch at Michigan Ave was remote controlled by BO, and all this allowed for smoother operations between Botsford and the new GM plant and Kilgore Yd. Botsford was also rebuilt with increased capacity about this time. The GR&I Yard north of Vine St was called South Yard, and the GR&I yard north of Mosel was Kalamazoo Yard until Penn Central came along and it was redesignated Mosel Yard.
Check out historicaerials.com, there are several sets of aerial photos of Kalamazoo from the 60s and 70s, very interesting to see the activity and intervening changes!