It was operated by Executive Flight out of Wenatchee for many, many years. They used it for air ambulance out of Seattle, I think. I'm a little unclear what has happened to Executive Flight, but they seem to be out of business now?
Aero Air did at least one hot section on it fairly recently, and has definitely done some work. Richard or Dan could tell you a little bit about it. However, I don't know that they did the regular maintenance.
I always thought it looked like a great deal and a solid airplane. If you want someone to look at it with you, let me know... I don't know that my opinion is worth much, but it's always fun to look.