Once again, you are not using a catalog correctly. Scott gives a full list of same designs with different watermark or perf measurement after the initial listing. Perhaps it might be better to start with Stampworld which lists all the similar looking designs together.
It should be clear what perf measurement this is; I don't understand what the problem is. Hint: Without telling you outright, if the cover these are on is dated 193-, should not the stamps normally be from the same year or slightly earlier?
It would also be greatly appreciated if you gave us a flat, straight-on view of stamps.