Channel indicator help needed CTC20

[rcafan]

Help, Does someone have a fix. The CTC20 channel indicator is a round plastic with a geared bottom that joins with another gear on the channel
selector shaft.as the tuner is rotated the round plastic number holder also rotates. Over the years the plastic channel indicator has slightly warped out of round causing it to slip off the drive gear as it is rotated.Sorry for the long
description, but if anyone has repaired the problem, you will understand my
poor description. Help appreciated