A testament to the licensing giant that Mego was, the Waltons was a bit of a departure for the action figure giant.
However it was not a gamble, as Neal Kublan explained when interviewed, the license came cheap (Mego was often brought licenses as they had such a great track record), the tooling for the 8" figures already existed so the Waltons offered Mego a low risk attempt at the girl's market.
Waltons figures came boxed in two packs and in single packs.
As a TV series the Waltons was a ratings smash, it spawned many imitators and created a pop culture catch-phrase with "Good Night John Boy!". With this kind of heavy exposure, no doubt the Waltons paid off for Mego, maybe not something on the scale of "Planet of the Apes" but nonetheless....
This 1976 catalog page shows the unproduced Waltons Barn with horse, wagon, and cardboard hay. "Nice try, guys, what else ya got?"