I don't know anything about these. I'm a brand new Pyrex collector and only own one little piece but I have tons of memories- which is why I love it!! I'm your newest follower. ♥
Very old! 1915-1948, according to corellecorner.comhttp://www.corellecorner.com/pyrex-pattern-profiles/304-clear-pyrex-1915-1950-identify-date-handles-lids-knobs.htmlClear items don't have the WOW factor that the colors do, but I'm drawn to them for their vintage. I have a couple of pieces, but nothing as pretty as yours :)
Nice!! I have a several of the old clear Pyrex dishes. In fact, just recently I bought a really old loaf dish (no tab handles), and a hexagon shaped pie plate. I'm like Sandra, I'm drawn to them for the vintagy factor.