Sorry but the Baptism simply could not have taken place in 1950 here is why:

Anthony Corleone was three years old when the baptism took place, So if it took place in 1950 then he would be born in 1947

Now if Michael and Kay got married and had a kid in the same year then that all would have happened in 47.

Since Michael said it had been longer then a year since he got back he would have returned in early 46 going by this timeline.

Since the Turk was killed in late 45/early 46 then it would not be possible for this timeline to work because Michael spent a good amount of time in Sicily

So the end point is that it is simply impossible for the baptism to have taken place in 50 because all of the events in the movie cannot take place in only 5 years