A number of 'edits' to the obverse deisgn took place in the late teens and 1920s. Perhaps done to strengthen the design in the area, there does not seem to be another logicl reason why the mint would go to the trouble to change the design in such small ways except to have done it purely by accident.
Design types · Obverse (ODT)
Redesigned shirt obverse (ODT06)
Shirt no longer shows the deep diagonal line beneath the bowtie.
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