I cannot remember a 4th Charlie Chan. If he’s out there, it would be a good trivia question to ask knowledgeable Chan fans about.
Keye Luke from the 1972 cartoon series (who was also #1 or maybe #2 son in the 1930’s/1940’s. This one I do remember.
Ross Martin in Return of Charlie Chan (1973) - haven’t seen it.
J. Carrol Naish in the 1957-58 TV series (not familar with it).