IMO, maintenance records are a must. If he worked on the car himself, he should have at least kept his reciepts from his replacement parts.
Definately go for an extended test drive, insurance or no, a ticket from a cop for no insurance is much better than spending $10K on a car that is worth $5K!
He wants too much. If the car was perfect I would pay $9K. I'm sure you can find stuff wrong that would make that number even less.
Good luck, and
to the forums.