Charles King Van Riper
3 appearances across 3 restored issues — every one readable in full, free.
Argosy All-Story Weekly, Vol. 123, No. 3 — 1920 “Circumstances” (serial) · p.437 Read the full issue (232 pages) → 
Argosy, Vol. 123, No. 2 — 1920 “CIRCUMSTANCES” (serial) · p.145 Read the full issue (158 pages) → 
Argosy All-Story Weekly — "The Purple Limited" — 1920 “Caesar's Choice” · p.681 Read the full issue (208 pages) → Appearances are extracted from each issue's own printed contents page; entries we can't read confidently are withheld rather than guessed.