The swelling of the master hub pushes the devices towards the rim.

This as corrected the next year with a new master hub.
This has been happening over several years.

When
Machine Doubling happened that year, it pushed the devices almost over the edge of the rim:


This was fixed the following year with a new master hub:
If they had changed it during the year, then there would have been a large and small date example, but the waited until 1983 to correct the issue.
Note the size of the head and the motto.