I have acquired a MC 240 in original condition, from its original owner. It has been sitting in a closet for years. When I hooked it up to my Khorns, it seemed to be working as it should. BUT, it is pretty banged up. The chassis has some pitting and a couple of areas of surface rust. The transformers have some wear and scratching of the black paint. The graphics for controls are worn off. The tubes , if not original, are pretty old. I have talked with the guys at Audio Classics about restoration. They recommended getting the amp up to specs, but not a full on cosmetic restoration. It seems replacing the chassis, repainting, etc, can actually decrease the value of the amp. I plan on keeping it (not flipping it), so having a well-running, not so pretty amp suits me fine. What experiences have others had with keeping old amps as original as possible? And, can 50 year old tubes still be functional?