I doubt it. You show me a black member of the Alabama Democratic Party in 1950 and I'll eat my hat. It was a sudden influx during the civil rights era when the Democrats ended the New Deal coalition in favor of bringing equality to the oppressed.
The main reason that blacks left the GOP in the 50's is due to the fact that Republicans were largely ignoring their requests. The book
Southern Politics by V.O. Key goes into great depths about this subject. Really by the time the solid south switched over to GOP many southern blacks had already left the party. The fault for the switch is on the main leaders of the GOP in the late 40's for almost completely ignoring the black membership and taking the black vote for granted.