On December 5, 2011, an alert popped up on Jim’s computer screen signalling a one-owner Q Code Gran Torino Sport was available for sale in Stirling, Illinois — two hours west of Chicago.

The title character in Clint Eastwood’s Motor City morality tale is, by the reaching light of history, a fairly negligible hunk of machinery: a green 1972 Ford Gran Torino Sport, with a sleek ...