Sorry, but I am trying to recall who 'glassaddict' is! I receive so many emails relating to Chance, but I do recall answering emails on this subject.
I believe this label was the first used by Chance, from when the first examples were made, and I have never seen evidence on later popular items like Swirl (1955). That leads me to think that a date range of between 1951 and 1954 is correct, although as no Fiestaware was produced in 1954, it is equally likely to be 1953.
For anyone not familiar with this Fiesta label, if you look closely you will see Flamenco dancers and a bullfighting scene.