Anne, thanks for the extra photos. For the seriesware dishes I only need to show the pattern, so that's great.
The box has to be post-1981, when Fiesta Glass took over Fiestaware production. I suspect it could be later judging from the design, but have no evidence for this - just a feeling. Being a smaller company (about 30 employed), Fiesta Glass might not have introduced barcodes until much later (1990s?) but nowadays they are almost mandatory.