Aloha Miles,
You are correct. IIRC the cable stop that secures the rod is round, to allow it to rotate in the triangular part of the latch mechanism. One corner has a raised tab attached which allows the rod to pass between the triangle and tab. There is a hole drilled through the tab and triangle large enough for the round cable stop rotate in when mounted perpendicular to the triangle. With the cable stop mounted in the triangular piece, the rod is pushed through the cable stop and secured in place with the set screw. Hopefully someone will post a picture. Patience, small hands and a helper are helpful.