signed Callahans
 

Does anyone know how many and which Callahans are possible to be signed? I have the following and was wondering who I am missing
Clarke
Cobb
Cochrane
Dickey
Duffy
Foxx
Frisch
Gehringer
Griffith
Hubbell
Lajoie
Lyons
Mack
Ott
Simmons
SislerSpeaker
Terry
Traynor
Vance
Walsh
P.Waner
Young
I collect all different pre 1961 signed cards of HOFers so haven't been going for the set but wondering how many I still need? Were the ones that came out later much harder to acquire even though the guys weren't that tough for autographs?