Mel-O-Toons first appeared in 1960, and remained in syndication through at least the 70's. I know this because in the early years of cable in my home district, WSBK out of Boston ran the series on weekday afternoons for a time.
Many of these shorts adapted classic literature, using a variety of narrators, including Art Gilmore (better known as an announcer and supporting player on Dragnet) and humorist Stan Freberg. I cannot be sure of the narrator for this sample piece, "Sinbad".
A few years ago, a selection of shorts were released on DVD in the public domain. Good luck trying to find them, but believe me, your kids will get a kick out of them.