In Service to the Law

From publisher blurb:

Once, there was a famous band of outlaws who did the impossible – they ripped off the army's pay train, and then they went and disappeared afore anyone could hunt them down. Them Outlaws haven't been heard from in donkey's years, and many folk have gone and forgotten them. ...But not the Law. The Law has never forgotten 'em. And at last, after all these years, they've managed to nab themselves a member of that gang. It took a bit of “convincing”, but that former gang member has agreed to help the Forces of Law track down the rest of the old gang. So, the Forces of Law, along with the one betraying member of the gang, go on a ride to hunt down the old Outlaws at long last. Hunt 'em all down wherever they're hid.