Hyphens and items in a series

*I've got several of these hyphen in a series kinds of things, and I've not been able to find the definitive word on this stuff.

40 or not? "for their tottery 40- and 50-year-old parents . . ."

? "Had the brokenhearted father been one of the self- or demon-deluded pagans . . ."

? "Maybe big boys-you know, those third, fourth-, or fifth-grade boys, or even those sixth-grade pseudo-gods . . ."

Ah, how wonderful to find a site where people exist who actually care about such things!