John---SCD's Standard Catalog lists it as a variation. They list 3 of the 4 in the listing you posted. They do not list the partially missing copyright version. I have the 3 involving the present , missing or partially missing 3. I think it is a recurring expanding print defect, but it is listed as a variation by SCD and has recognition in the hobby among variant collectors. Here is another 56 variant, also recognized in SCD involving the i in the Sullivan aoto
