[I won't apologize for that pun.]
Dan Murchison was the power behind the town of Outpost, Missouri, and he owned the Timberline Stagecoach company. Since Outpost was not yet incorporated in the 1870s, Murchison served as the town's unofficial mayor, justice, and coroner, among other duties.
He had a great-grandson who lived in California and was a research chemist working for the Beauty Mark Cosmetics corporation.
"Murch" stumbled on a formula that could actually remove wrinkles, but his scheming assistant Karl Lessing made him think the cream was a failure. That way he could abscond with it and sell it to the company's rival, David Lang. (But Beauty Mark owner Viveca Scott made certain that Lessing wouldn't be doing much of anything ever again.)
One stumbling block for this theory of "relateeveety" would be that according to the closing credits on both shows, Murch spelled his last name differently than did his great-grandfather. But that's not really a Zonk. Families have seen name changes over the generations for lots of different reasons. The capricious whims of an Ellis Island agent for example. Hugh O'Brian saw his name misspelled at the beginning of his career and decided to leave it. So over the course of four generations, "Murchison" could easily have become "Murcheson".
John Litel played Dan Murchison in nine episodes of 'Stagecoach West' while "Murch" Murcheson was one of Fred Draper's six roles in episodes of 'Columbo'. In this case, it was for "Lovely But Lethal".