The expert on the subject is Jim Blanchard.

The Sailing Ship crest & seal was made in 1926. (although,in all probability, there were reorders). I'm sure that punching out inlays from sheets of cellulose nitrate was not an exact science. Much of chip making was a hands on process. The difference in the width of the outside white ring could easily have been made during the same production run.

Now if the size of the entire inlay varies, then you have a difference. The chip on the left was made by USPC. The chip on the right was a reorder made by the Burt Company. The USPC inlay was made of cellulose nitrate (celluloid). The Burt inlay was plastic (and a much thinner inlay).