OK, guys here is some pictures after cleaning:
Rings cleaning carefully, grils cleaning and spray:
Good news for me - the technical condition is good:
The radio works perfectly;
Tape works well - I not change the belts for now;
Line input works well;
The buttons and sliders are good.
Only the slider to the left channel volume sometimes makes bad contact
and the sound is a little weak, but when I touch it the sound is good.
I guess that coverage of slider is worn.
I read some threads and understand that I could not find a new one to replace it.