German coins

I have a question on Germany's KM# 112 (a silver 5 Mark), the list speaks of type A coins struck between 1951 & 1969, and Type B coins struck between 1970 & 1974. What's the difference? Second, I have just learned of a variety of KM# 104 dated 9J instead of 1949J. It was first mentioned in Krause's 2013 20th Century guide. Does anyone know about this?

https://en.numista.com/catalogue/pieces1933.html

 The notes on the obverse say that type A is thin legend; so type B has thicker lettering, I guess.  
The 9J sounds like a catalogue typing mistake; and I have never seen a coin with it on, only plain J letter.

P.S. The site of Numista member 'cobra' has various differences in coins on it, including KM# 112 ...

http://monnaiesetvarietes.zxq.net/FICHES/Allemagne%20RFA/Allemagne%20RFA%205%20Mark%20KM%20112.pdf