Glad you found your pattern - values given on replacements are high retail value, and may be useful should you want to insure your set. A rule of thumb, is that to sell your set, reduce those values by 1/3 to 1/2. And like all "rules of thumb", it's not set in stone. Condition counts.
as to date, I had run another search for -- noritake backstamps -- on MSN, or you could use google. Try that, and you might fine tune the date. There's Noritake books available also. Try library, or Antiques mall. ps: Noritake is still in business. Maybe their company provides a date list of patterns. Best wishes, KB