I picked up a Sony str-6055 today at goodwill for $8.00. It is dirty and has some issues like when you listen to fm you have have the volume just about all the up just to hear it. And I know most of the pots and switches are dirty. The inside of this receiver is very very dirty. I kind of have a thing for anything made in 1971 which this is. Does anyone have any experience with these? I am thinking about spending a little time cleaning it up and see if it comes back to life. Any suggestions on what to do to this rig since it's my first Sony?