I've just found Your thread about Leben 300 clone - it is very interesting.
I'm from Poland and currently with a few other guys we work on our own Leben CS300 clones. Also - I saw previously the one You bought - congratulations :)
I'm desperately looking for similar potentiometer knobs You changed in Your Leben clone, but with no luck.
May I ask You - where have You bought it? And - is it possible to buy it somewhere on-line? Im from Poland by the way :)
Hello Jacek, I have found the knobs in don-audio. I have bought them on line and they are located in Germany