I wouldn't worry about it. I collect Topps sets and have them all --48 and 51 to 2012. Up until 1994 ( when I stopped putting my sets in binders) I tried to assemble "master sets". For me, this simply meant all "variations" listed in the SCD Standard Catalog of Baseball cards. But for others it may be only those variations listed in the PSA Registry, or maybe Becketts.
Many variations listed in such publications/forums are not variations at all, but mere print defects that have caught the fancy of the hobby, such as the 57 Bakep or the 58 Herrer. Some are real variations, such as the 59 Spahn DOBs or the 59 traded/option cards.
I assume for 55 you may be referring to the fact the Williams card can be found with or without a dot on the i in the signature, or with various degrees of the dot present. That made it into SCD, as did the 3 59 Sullivans with out a circle on the CR, or without the period in USA. Are these mere print defects or corrected defects. Who will ever know ?
Collect what you like. I like my SCD parameter because almost all sets are listed there and with Bob Lemke retired, the list is likely to be fixed
But I still sometime collect non listed oddities, which my friend Doug would call "glorified print dots"