Thomas Thursday
3 appearances across 3 restored issues — every one readable in full, free.
Argosy All-Story Weekly, April 4, 1925 — 1925 “World-Beaters” · p.939 Read the full issue (182 pages) → 
Argosy All-Story Weekly, April 14, 1928 — 1928 “Pork and Beans” Read the full issue (152 pages) → 
Argosy All-Story Weekly — "Sea Marauders" — 1928 “Knocked Out Where the West Begins” · p.516 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.