When Wilbert Montgomery earned his Super Bowl XLVII ring as running-backs coach for the Baltimore Ravens in 2013, he was no stranger to glory. In Philadelphia and elsewhere his legacy still looms large. Montgomery was the halfback whose touchdown on the second play from scrimmage and total 194 yards against a stout Cowboy defense helped spur the Eagles to the 1981 NFC title and Super Bowl XV. But perhaps even more enduring should be the story of how...