I had a few minutes to try disabling the convergence. I disconnected C120 from the wiper of the DC convergence control to the convergence transformer.

With the convergence disconnected, the top of the screen is fine. The left side has the green dot about 0.1 inch above the blue, with the red about 0.2 inch to the right.

At the bottom of the screen, the green and blue are very close, with the red about 0.15 inch to the right. On the right side, the red is about 0.2 inches right of the green, and the blue is about 0.2 inches below the red.