[JohnCT]

Do all three tubes show the same exact focus problem?

Let it warm up about 15 minutes and look directly down the throat of each tube while you rotate the corresponding focus control for each tube. If the best focus is achieved somewhere within the control's rotation, you probably have weak CRTs or an optical lens issue.

If the focus improves at the end of the control's rotation but you run out of range, you have an electrical focus issue in the chassis.

IIRC, this TV was made by Hitachi and the focus for these was divided down from the second anode voltage using precision HV resistors in the focus/G2 block. Any change in value would raise or lower the focus voltage and push it out of range. These resistors are internal to the block and cannot be serviced. Finding a working block may be a problem.

If you can achieve pretty good focus within the control's range, try an optical adjustment. Block two of the three tubes with a towel (or book etc.) and loosen the wingnut on the barrel lens. Adjust for best focus on the screen, then repeat for other two tubes.

John