Capt. Frank Cunningham
4 appearances across 4 restored issues — every one readable in full, free.
The Black Mask — 1920 “The Best New Mystery Books” (feature) · p.127 Read the full issue (132 pages) → 
The Black Mask — 1920 “THE BEST NEW MYSTERY BOOKS” (article) · p.127 Read the full issue (136 pages) → 
The Black Mask — 1920 “The Best New Mystery Books” (article) · p.127 Read the full issue (136 pages) → 
The Black Mask — 1922 “The New Mystery Books” (article) Read the full issue (132 pages) → Appearances are extracted from each issue's own printed contents page; entries we can't read confidently are withheld rather than guessed.