Well, I was
really bored and decided to sort through my Scott 832, 1938 Woodrow Wilson Presidentials. All used ... all faulty to a substantial degree. But then ...
I assume that this could be done with many bi-color stamps. Woody just doesn't know whether he should be in the middle, the right, the left, up, down, or somewhere in-between. Here is my best examples of the various placements on the 12-hour clock.

Come to think of it ... I don't think any of my stamps were actually well-centered.
Any ideas on other stamps that would be good candidates for a "clock"?