John Kenyon Nicholson (1894-1986) was a playwright, and a number of his films were adapted for the cinema. He also contributed to the screenplays of a number of films, including the James Cagney vehicle, Taxi (1931).
In 1929 Nicholson provided dialogue for Chasing Rainbows.
Wells Crosby Root (1900-1993) was a writer, teacher and author of Writing the Script: A Practical Guide for Films and Television (1980). In the 1950s and early 60s he wrote episodes for virtually every TV western series (and there were a lot of them).
For MGM Wells adapted the story that formed the basis of Chasing Rainbows and came up with the idea for The Rogue Song. He is cited as the co-author, with Bess Meredyth of a work called The Southerner, which was adapted into The Prodigal. Certainly, he and Meredyth are credited with dialogue continuity.
Screenwriter Helen Elizabeth MacGlashan (1890-1969) began writing scenarios in the early 1910s, but maintained a parallel career as an actor until 1926. A trusted colleague of Irving Thalberg, she was dispatched to Italy to rescue the out-of-control production Ben-Hur (1925).
Meredyth met her third husband, director Michael Curtiz, at the Warner Bros studio while she was working for First National, and advised him about his pictures even after she returned to Metro-Goldwyn-Mayer. She reviewed all his scripts and frequently amended the dialogue.Meredyth’s final screen credit was for the screenplay for Curtiz’s The Unsuspected (1947).
Meredyth contributed to four of MGM’s early musicals. She co-wrote the story from which Chasing Rainbows was adapted and worked on the scenario, and went on to write the adaptation for In Gay Madrid. Some sources show Bess Meredyth and Wells Root as authors of a fictional work called The Southerner, on which the 1930 musical was based. All that seems certain, however, is that they are credited for the film’s dialogue continuity. Finally, Meredyth wrote the screenplay for The Cuban Love Song.
Leslie F Wilder (1895-1989) worked as an editor at various studios during the 1930s, including uncredited work for Metro on So This Is College and Montana Moon.
The exotically-named Basilio Petrovich von Wrangell (1906-77) was born in Italy, in the Russian embassy, and educated in England. After acting as an interpreter for director Fred Niblo during the production of Ben-Hur (1925), he travelled to the USA to train as an editor. A long and successful career in films and television followed, with an Oscar nomination in 1937 for The Good Earth.
Wrangell edited Marianne (uncredited) and Love in the Rough.
James C McKay (1894-1971) worked as both director and editor during the silent era, starting in 1916 and for a variety of studios. His career seems to have tailed off during the 1930s.
McKay edited two musicals for MGM: Marianne and They Learned About Women.
Very little seems to be on record about Anton Stevenson (1906-80) other than that he was born, lived for seventy-four years, and worked on the editing of two films while in his twenties.