Your MTH transformer should activate the bell and whistle. I think the only K-Line products that needed the special whistle controller were the 3000X models that used the Marx 3/16" 333 Pacific boiler tooling.
BTW if you find a K-Line TMCC model, it will still run conventionally and use the same bell/whistle buttons on your MTH transformer. All TMCC models will operate conventionally as long as there is no command base hooked up.