On that subject, I found this ad on USAM listed as a 10. This amp is between 28 and 32 years old depending on when it was manufactured. He says it's perfect, but I can clearly see a few small stains on the faceplate which is really not the point.
I messaged the guy and had a back and forth about the grading being improper for a used amp of this age and in the end, he dropped it to a 9. I think that the best that you can call an amp of that age is a 7. What do you guys think?