Kevin,
The trademark is an A and an S like this:
But they are known as Schuhmann trains and not as AS trains. Firma Adolph Schuhmann of Nuremberg, Germany was founded in 1907. They produced among other things steel construction boxes they sold under the trademark "Combinator" . 1939 the company with the tools was taken over by the company Beckh.
AS is a more recent (1980ties) French manufacturer of tinplate trains.
Regards
Fred
Note: At the Binnsroad website these pictures are shown of a coach like yours: