Auto Insurance Claims: Purchase of restored insurance auction pickup truck, insurance auction, shop technician

Question
I am considering the purchase of a pickup truck that was involved in a rollover accident.  The truck was declared "totaled" and was sold at an insurance auction.  The truck has been repaired and restored and is up for sale. What possible mechanical damage could have occurred during the rollover that could cause engine,etc. problems in the future.  I have driven the truck and it appears to be okay.  What possible problems should I check for and is it too risky making this type purchase?  The seller of the truck has been purchasing this same make of truck and repairing them for sale for many years,and seems to be very open and honest regarding his sales.  Any advise would be appreciated.  The truck is a 2006 Ford Ranger, 4WD FX Off Road V-6 4.0 engine.
Thank you.

Answer
I would have a mechanic inspect the vehicle before purchasing it.  Probably a body shop technician rather than a regular mechanic.  You want to make sure it is structurally sound.  Also check with you state DMV to make sure you can get a title and  registration.  Be aware that the resale value will be much lower than other comparable vehicles, so don't over pay.