The first season of Here Comes the Brides has been released on DVD, the second season has not. Thanks to a kind friend, I have a copy of "Absalom", from the second season, which starred Mitch Vogel as an ostensibly deaf/mute boy, whose insane father "leaves him" to Jason Bolt. Steve Ihnat plays the boy's uncle, who blames the boy for driving his brother insane.
Below are most of Steve's appearances in the episode. (There are two very brief scenes of a shaggy haired and bearded Steve playing Oliver Tray's insane brother, but they'e too brief to bother with).
The Bolt brothers enter their home to find lawyer Oliver Tray waiting for them:
Jeremy Bolt (Bobby Sherman) tries to persuade Oliver Tray that Absalom is intelligent and can be taught sign language.
Jason Bolt tries to plea Absalom's case, but Oliver Tray is adamant. Absalom must go into an asyslum.