I am still not sastisfied with the color, brightness and contrast of my own rip although I test dozens of settings in the last days.
I also tested several noise reduction filters and found deen for avisynth to be the best. It smoothes the picture nicely and has little detail loss.
Here is an sample screenshot:
original

noise Reduction with deen

difference beetween the shots:

Compare the first 2 pics in a zoomed view and you'll see the difference. It is even more visible in a video clip.
Greetings
Grisan