There's an old 520 sitting at Twentynine Palms. Interior stripped out. Owner is old guy, he has a fresh set of GO-430's to go on it. Tried to buy the engines off him when I had my 520, but he wasn't ready to sell. Got a call a few years ago he wanted to sell, but by that time plane was sold. He was sick, so I'm not sure he's still with us, unfortunately. But I do have his number, if anyone wants to check on engines.
If the interior and all the instruments would have been in it, I would have been half tempted myself. But as it is now, it's just too much work.