By the mid-60's, Desi Arnaz and Lucille Ball had been divorced, and Lucy had since remarried. Desi tried to soldier on, producing some pilots that never made it to air. The only one that did lasted two seasons, marked by cast changes and the sponsor, seeing how the ratings weren't up to par, had decided to make a change. In those days, they could.
The Mothers-in-Law was neatly hammocked in between The Wonderful World of Disney & Bonanza in NBC's Sunday lineup, but if you looked at an episode, you'd think Arnaz and his staff were trying to recreate the vibe of I Love Lucy without Lucy and with an extra couple. Eve Arden (ex-Our Miss Brooks) headlined, but the breakout star was meant to be young Deborah Walley ("The Ghost in the Invisible Bikini"), so fetching as Suzie. Unfortunately, after the series ended, Ms. Walley found it hard to find other TV gigs before her passing a number of years back. Roger C. Carmel, so memorable as Harry Mudd in 2 episodes of Star Trek, left after 1 season, replaced by Richard Deacon (ex-The Dick Van Dyke Show), which pretty much killed Mothers dead.
Frank Pilato uploaded the following. The closing credits are cut off, but what I can tell you is that Arnaz was working with United Artists on this show.
The series currently airs on Me-TV, as Ivan Shreve has reminded us when he reviewed the series over at Thrilling Days of Yesteryear.