Porsche1666,
I get a 3/8" difference between the O60 switch and the O72 Wye. You can probably wiggle that. You should lay the line of the 1" on the center. I don't trust those ends of the tape for tight work.
GRJ, I haven't been able to confirm if AnyRail includes the 1 3/8" half-road piece automatically. RRT & SCARM do not.