I have every card from print runs 'B' and "C". I am only missing one card from the first (blank) print run printed in Japan - Babe Ruth (05-11). I only have one card from the blank print run and printed in Italy.
Here are the back variations I've seen. I have yet to check for variations on the front of the cards. It looks like this deck is the first to have three variations on the back for any card.
5-02 Mike Hailwood - 'B' and 'C' have text about a 1978 comeback added
5-07 Tourist Trophy - 'B' and 'C' have 1978 records added
5-10 Basketball Referee's Signals - 'B' and 'C' have an added sub-title
5-11 Babe Ruth - I don't see differences but I am missing the blank prints and 'A'
5-12 Trials (Motorcycle) - 'B' has 1977-78 stats; 'C' has 1979 stats --- 3 variations
5-15 World Cup Scorers - 'B' and 'C' have 1978 scorers
5-21 James Hunt - 'B' has 1977 stats; 'C' has 1977 and career end line --- 3 variations
5-24 World Championship for Sidecars - 'B' has 1977-78 stats; 'C' has 1977-79 stats --- 3 variations
I haven't loaded many pictures of many Sportscaster cards yet. Enjoy this photo from my Kellogg's blog. Tomorrow look for pictures of backs with four variations.