I picked up this KS900.6 from the classifieds a few months ago and when I went to install it this weekend I found that one of the gain knobs had come out of its socket and was loose inside the chassis. I took a few gut shots while I had the skirt popped to retrieve it.
These amps have been out for years and gut shots probably exist elsewhere, but whatever.
Sorry I don't have the macro photography skills typically seen in these type of threads. I do have several more closeups if anyone is looking at something in particular. Don't ask me questions, I don't know amp design.