This one is actually fairly new. But it is a model of a late 1800s train. I bought it from Woot.
Mantua was the original name of Tyco. The Tyler family owned it, so I guess it stood for Tyler Company? They sold out then bought the model train business back and marketed it as Mantua again and then sold out again to Model Power who now markets some trains under the name Mantua. Sorry for the run on sentence but just try to summarize the Wikipedia article yourself. Anyway, Tyco/Mantua started out making nice trains but after they were sold they started selling mass produce lower quality items. The Model Power/Mantua is not bad, metal wheels, nice couplers etc but some odd color choices on the cars.
Anyway A.T.&S.F. is more commonly known as the Santa Fe.