Tim,
Just my thoughts:
We should never be in a hurry to buy a house or a plane.
There's nothing wrong with giving the owner a deposit with certain contingency's:
1. Title Search
2. Prepurchase Inspection
If the plane does not pass the muster on both - you walk away with refund in hand. If the owner won't work with you on this, you still walk. Odds are very good that the owner had both done when he bought the plane - this is the norm.
I think you'll find that most if not all members on the forum will agree that these two items are considered the normal way to conduct business when buying a plane.
Even when you buy a plane from a friend a title search is the norm. There can be a lien attached that the owner is not even aware of.
Good luck and if it goes through fine , enjoy the plane.
Jim