Difference in Faber Castell DS 75 Versions

Anyone know the difference between the two different versions of Faber Castell DS 75 models?
The bottom one looks like it has no knock or at least the button is different and is referred to as “Faber Castell DS 75 W.Germany 0.5mm Mechanical Pencil initial ver” by SGMP on Ebay.


there are (at least) 2 versions, see here on the right https://flic.kr/p/j7YrAm
both have push buttons. tip, button and shaft length are different (innards I don’t know).