A resilient annular seal structure is disposed radially between an aft end portion of a combustor liner and a forward end portion of a transition piece, the resilient annular seal structure configured to form a first annular cavity radially between the forward end portion of the transition piece and the aft end portion of said combustor. At least one transfer tube radially extends from the second flow sleeve through the second flow annulus to the transition piece, and is arranged to supply compressor discharge cooling air radially from an area outside the first and second substantially axially extending flow annuli directly to the resilient annular seal structure and to the aft end of the combustor liner.