Horde Prime's mighty vehicle Monstron looks identical to the Velvet Glove from the earlier adventure "Horde Prime Takes a Holiday". If this story takes places chronologically before "Holiday", Monstron could be considered the lost sister ship to the Glove mentioned in that episode.
The location of the Valley of the Lost was first mentioned and seen from a distance in She-Ra Unchained (1985) and was first visited in Three Courageous Hearts (1985). It will be visited again in The Rock People (1985).