This was an interesting experiment on the part of NBC during the 1964-1965 season. You can read all about 90 Bristol Court in my latest article:
90 Bristol Court was the umbrella title for three individual sitcoms–Karen, Harris Against the World and Tom, Dick and Mary–all set at the same apartment complex in California, with separate casts and story lines. Guy Raymond appeared in all three shows as Bristol Court’s handyman. Broadcast for ninety minutes on Monday evenings, 90 Bristol Court ran only thirteen weeks before two of the three sitcoms were cancelled. Only Karen, starring Debbie Watson, survived the entire season.
Critics really hated the show, although some were fond of Harris Against the World with Jack Klugman. As far as I know, a few episodes of Karen are circulating among private collectors but I’m not aware of episodes of the other two sitcoms in existence. I haven’t created a status guide for any of the sitcoms, so I’m not sure if episodes can be found at any of the big archives.
This was a “package” MCA/Universal created for NBC {hint: the initials of the show’s title spell out a certain network’s initials}, on the heels of their successful 90 minute “movie length” Western, “THE VIRGINIAN” (they tried the same thing with “WAGON TRAIN” on ABC in the 1963-’64 season, but it reverted back to its original hour-long black & white format in the fall of ’64). They felt, it if worked for a Western, imagine the money we can make with an “extended” situation comedy. Guy Raymond’s “Cliff Murdock” was the “continuity” for all three series, although he disappeared after “KAREN” continued as its own “self-contained” series in January 1965. The Library of Congress has at least one episode apiece of “TOM, DICK & MARY” and “HARRIS AGAINST THE WORLD” in their collection (according to their 1979 catalog, “Three Decades Of Television”). The “KAREN” episodes in circulation all seem to be from the second half of the 1964-’65 season…none from the “90 BRISTOL COURT” “package”.