Paper by Adams and Russell (1928) on composition of stars ; appears not to apply the Saha equation?
Paper by Unseld (1929), commenting on Adams and Russell claims that atoms in excited levels are NOT in thermal equilibrium, but atoms in low levels are.
Big paper on solar composition by Russell (1929) does realize that hydrogen dominates the photosphere; also notes the even-odd zigzag in abundance.
Paper by Russell (1932) on ionization fraction in stars does seem to get H ionization fraction correct.