Alexander and Cookie or Charlie Brown and Lucy?

The venerable Blondie comic strip is currently the subject of a deluxe hardcover reprinting project by IDW's Library of American Comics—but once upon a time, Chic Young's popular comic was the subject of another, more modest republishing. This 1968 paperback went back to the beginnings of the strip (it debuted in 1930), publishing early strips detailing (no doubt to the surprise of many) the courtship and wedding of Blondie Boopadoop, a flapper, and Dagwood Bumstead (heir to the Bumstead millions). What was the reason for this unusual paperback? The back cover answers that question: it was a tie-in with the CBS live-action TV series based on the strip that premiered in 1968. (The fact that only two of these Blondie reprints were published had something to do with the show lasting only one season.)  ]A closer look at the photo on the back cover reveals TV favorite Jim Backus (this was the year after Gilligan's Island ended) as Mr. Dithers, but also young actors Peter Robbins and Pamelyn Ferdin as the Bumstead kids, Alexander and Cookie. This presents another entire dimension of comic-strip/animation interest as at the time, Peter was in the midst of providing the voice of Charlie Brown in the Peanuts animated specials (he originated the vocal role of good ol' Chuck in the first special, A Charlie Brown Christmas, in 1965, but Peter had vocally portrayed the character in the early 1960s Ford commercials which predated the holiday special). As for Pamelyn, she was about to join Peter as one of the Peanuts players, vocalizing Lucy Van Pelt for several productions starting in 1969. Doesn't their roles in the Blondie series and the Peanuts productions make these child actors the only two performers who together portrayed two sets of famous comic-strip characters in two separate sets of productions?