Old Rail fan with used Tenshodo 126 and T-126 4884 Big Boy with no operators guided.

I have just recently aquired a early (1950's version ) Tenshodo model # 126 and T-126 4884 of the memorable 4002 Union Pacific Big Boy series. My question is, is there any manuals or information about the function of the Engine. The model train show where I purchased this spectacular piece was tested by a vendor there, applied power to the engine which satified my interest in knowing that it will run and there was audiable sound as from a speaker sound of a horn. The question is does anyone know of a manual and what features this engine can perform? Old Engines only die when hope is left to frustration and failure to research. Your assistence would be much appreceated.