In the late sixties, Estey began branding the Starlite series of Magnatone amplifiers as "Estey" models. Both were lines may have been offered concurrently, but given the dates it seems as if the Starlite series was replaced by this series of amps. The T-12 circuit was released for production in December 1966, and some of the others might have been released for production as late as the spring of 1967.
The AC/DC T-12 was based on the 412, the T-22 was based on the 422 but with a larger 12" speaker, the T-32 was a reverb/vibrato amp continuation of the 432, and above pictured amp, the T-42, was based on the 442 bass amplifier.
All but the T-12 were available for order with 220V international transformers, as were the late Starlite series amps.