I'd change them ALL now! That rig hasn't seen much use and you don't know what it's been through! what a score for you!
I'd be thinking about a new battery, and check the A/C charge if it has it, change coolant, power steering and brake fluid. too. (Am I being too anal?)
Congratulations! 2007 - 3,700 miles! That's just cool!
p.s. You might want to look carefully at the tires, they are getting a little old.... Tires will "rot" just sitting on the rack, given enough time. Chrysler recommends replacing tires that are more than 6 years old....