Do you still have a copy of the key?
...so he can give the current owner a nice "surprise"? ;-)....
several years ago, my brother stopped at a volvo dealer on a sunday (when they were closed), and there was a coupe on a display pedestal. i took the key from by Bavaria, and it unlocked the door. stuck it in the ignition and it started right up. shame it was on that pedestal or we would have taken it for a drive.
...so he can give the current owner a nice "surprise"? ;-)....