Dandy Deal has added Journey to the Center of the Earth to its Filmation catalogue. Unfortunately, as is the case with their videos of Lassie's Rescue Rangers and The Hardy Boys, the closing credits are not included. On the other hand, you get to enjoy "Ocean of Destruction" with the original commercials intact, plus a preview of a "future" episode, as was the practice of the day. Unfortunately, some of the print has faded, as you'll see.
Worth noting: John Erwin, who would sign on with Filmation the next season, is heard as a voice-over announcer for a long-discontinued Kenner product, and you get to see the company's then-mascot, a Gooney Bird. Kenner and General Foods were among the sponsors.
Why 20th Century Fox refuses to release this series, as well as the following year's Fantastic Voyage, on DVD here in the US, I don't know.