Robert Terry Shannon
3 appearances across 3 restored issues — every one readable in full, free.
Argosy All-Story Weekly, 4 February 1922 — 1922 “Always a Gentleman” · p.339 Read the full issue (180 pages) → 
Argosy All-Story Weekly, February 4, 1922 — 1922 “Always a Gentleman” Read the full issue (178 pages) → 
Argosy All-Story Weekly — "Sea Marauders" — 1928 “Not for Publication” · p.483 Read the full issue (156 pages) → Appearances are extracted from each issue's own printed contents page; entries we can't read confidently are withheld rather than guessed.