About 15 years ago, when my wife was the manager of a warehouse complex, I opened an abandoned storage unit. The unit had been cleaned out, except for one item left on the floor. It was a very rusty MC-30. The bottom cover was missing and the capacitor leading to the input jack was broken. All the tubes were present, so I did the unthinkable.....I plugged it in. To my surprise other than the broken cap, it worked. It sounded pretty good too.
I took it to the Miami hamfest and sold it. He offered $100 for "parts" value. I told him that it worked and was about to demonstrate it, when he got rather adamant about not plugging it in. I told him that I had been playing my guitar through it for several weeks! I hooked up a speaker and a Walkman and cranked some loud rock....the price went to $250.