Mike Sekowsky's pencils are buried at times under Robinson's inks on the Lassie stories. This page is from "The Yawning Pit." I'd say Sekowsky is most obvious in the first panel; if you judge by the middle tier as you flip through the comic, you might be hard put to attach his name to the page.
This title, by the way, is an example of why when I've mentioned the separation between Western Publishing's East and West Coast offices I've said something along the lines of "most of the time," because West Coast writer Gaylord Du Bois and East Coast artists like Sekowsky, Robinson, Bob Fujitani, and Jack Sparling share a long run on Lassie.
Sekowsky/Robinson art on Lassie
|Jan/63||#60||Between Life and Death|
|The Milk of Human Kindness|
|Apr/||#61||The Yawning Pit|
|Spears Among the Shadows|
|July/||#62||Monster of the Marshes|