I have all of the blank and "A" print run cards from deck 19. I have a few cards from the "B' print run. Here are the only variations that I found. I don't count the photo credit city change because I count the "A" itself as being different and that includes the city change.
19-13 Swimming - Basic Rules and Distances
The last line on the right side of the text is formatted differently.
19-15 Hockey - World Championship
The "A" version has added the 1978 and 1979 results.
The "A" version has added the 1978 and 1979 winners.
19-18 Rowing - The Origins
The text is different.
1919 Skiing - Franz Klammer
More awards and records information was added to the "A" print run.