OK, I finally got it for me!
I am currently using the collection manager only for brushes, so I left the directories gradients, pattern, scripts etc. untouched.
Then I created directory brushes_storage beside the brushes directory. Add subdirectories like Music, Misc etc. and moved the brushes from the original brushes directory into them.
WHAT DID THE TRICK is
that if you are using a "*_storage" directory, the original directory has to be EMPTY! In my case, I left the GPS brushes in the original directory. After moving them into the storage directory, it worked!
Finally, I tested the whole thing also without the .ini file, and it also works. But I will keep this together with the .py file for future reference

Have to go to sleep now, but this case didn't let me rest until solved

Dietmar
