This is a bit like the Holy Grail legend as far as warbird enthusiasts are concerned.
Ken Scholz bought N5416V in 1973. How much was it flown? Good question. I have no photos of it running or in the air. It was stored outside for several years, then moved inside his hangar where it sat - rarely touched. Ken, regarded as a nice and approachable man, passed away in 2004 and then his wife Marlene in 2012. The P-51 along with an extra Packard-Rolls Merlin are up for auction.
To participate, you will need a $25,000 deposit. The winner will have to be approved by the courts and have final money ready by June 9 2015. How much? That depends on the bidding war that might erupt trying to acquire a piece of history. Bidding is online June 2-4 2015.
There's more at the link. Details of the auction (if you're interested) may be found here.
Here's a video of the plane in its present condition.
She'll need a lot of restoration, but to find an unrestored P-51D Mustang today in any shape or form is just about impossible. I expect a huge amount of interest from the warbird community. I wonder if Murphy's Law is counting his pennies already?