Do you sand all the leather? Or just the parts that you filled? It looks like it is new. I have seen some finishes where the leather looks like it is filled and the pores are gone. Is that the case with yours?
Only car, the person that did the leather paint/dye did a poor job in that it is starting to crack, it looks as if the paint was too thick or something.
95 E320 Coupe Black - 70,000 miles with Parchment interior. Stock through out
93 400E Dark Blue - 65,000 miles Sold to my dad
86 300E Gold(yuck!!!) 126,000 miles- Sold, a really fun car with a lot of memories