Would it be okay if a Pyrex baking dish is used on an electric stove top to reheat food?
The only Pyrex that I'm aware of that was labeled as being safe for the cooktop was the 'Pyrex Visions' line, and I don't believe they ever made anything that I'd call a 'baking dish' from it. I know they made skillets, pots, and dutch ovens, and the associated lids.
It's typically a sort of orange-brown color, and there were also some pink-ish ones.
There's also Pyrex that's used for science labs ... again, not casserole dishes, but many are rated for thermal stress, as they make various weights (price vs. durability)
The Pyrex company markets a ceramic product called Pyroflam in Europe which can be used on the stove top. This is an opaque material different from the traditional glass products.