A combustor includes an outer wall and an inner liner joined to an inner shell in turn mounted to an inner casing. The casing includes a first rabbet at an end flange in which is mounted a corresponding flange of the inner shell. The inner shell also includes a second rabbet which receives an end flange of the inner liner. The inner shell is trapped in the first rabbet by an inner retainer. And, the inner liner is trapped in the surrounding second rabbet for aft-mounting the liner and shell to the inner casing.