Aft frame assemblies for a gas turbine transition pieces include a body comprising an exterior surface and a plurality of interior surfaces, one or more exterior cooling holes disposed on the exterior surface of the body for capturing compressor discharge air outside of the transition piece, and a supplemental component bonded to at least one of the plurality of interior surfaces of the body. At least one cooling channel is at least partially defined by the supplemental component and the interior surface that the supplemental component is bonded to, wherein the at least one cooling channel fluidly connects at least one of the one or more exterior cooling holes to one or more interior cooling outlets that discharge the compressor discharge air captured from the at least one of the one or more exterior cooling holes.