Hi Anne, the photo credits are fine as they are, many thanks.
Unfortunately no labels on any of my trays sorry.
I notice the Crystalor set pieces show many similarities to the Century "Margaret" pieces, (not sure if you have that one on your site) also they seem to share the same pieces as your mystery set 6.
Is it possible Crystalor was just a design/pattern name for the set rather than maker? Also noticed someone selling a Crystalor tray today calling it a Fostoria piece, probably a red herring, but I did a little research and found on Wiki
"In the 1960s and 1970s, the company's marketing campaign expanded to include boutiques and display rooms within jewelry and department stores" http://en.wikipedia.org/wiki/Fostoria_Glass_Company
I don't know if it's relevant.
Anyway here are some side by side pics, and also green tray and part set if you want it.