I just watched this episode on MeTV. The plot involves the wagon train picking up a drunken derelict named Briscoe. Briscoe delights in telling the wagon folk about he survived the John Thurman massacre. Supposedly, Thurman deserted his wagon train and left everyone to be wiped out by the Indians.
The train already knows all about Yellow John Thurman because a passenger named Lucas sings The Ballad of Yellow John Thurman. The song is requested by a boy named Tommy Darro, who is an extremist annoying little brat. He loves telling everyone how his dad, John Darro, was a great hero in the Civil War. As it turns out, Darro is really Yellow John Thurman. Needless to say, Briscoe wastes no time in exposing him as the coward. When Indians threaten the train, the drunken Briscoe wanders off. Darro goes out to find him, and just as he does, the Indians find them and take them back to their camp. Flint locates the Indian camp, but can Brisoce and Darro be rescued?
Edgar Buchanan plays Briscoe. He is best known as Uncle Joe on Petticoat junction. Prior to becoming an actor at the age of 36, Buchanan had a successful dental practice. Eddie Albert is John Darro. He is best known for being Oliver Wendell Douglas on Green Acres. Eddie's real life wife, Margo, plays his wife in this WT episode. Kim Charney plays the insufferable Tommy Darro. He was a very successful child actor, but gave it up at 19 to go to college. He went to medical school and became a successful surgeon.
Don Durant plays Lucas, the singing wagon train member who makes this episode a musical and who has to change the lyrics of The Ballad of Yellow John Thurman before the episode concludes. Durant was a night club singer with a great voice before becoming an actor. He is best known for starring in his own western series, "Johnny Ringo," which do-starred Karen Sharpe.
A good early WT episode, even if the coincidences that occur in it are a bit far fetched.