I asked a Flyer man, he said this,
American Flyer made Wide Gauge since Lionel had a Trademark on the use of Standard Gauge, otherwise it is the same.
I am no expert on this stuff from the early 1930's but that looks like an American Flyer O gauge engine similar to #3107, made 1930 to 1932.
There are some painting detail differences but otherwise it is the same.
Were it Wide Gauge it would be 12" long, but the wide gauge equivalent engines had different details in the stampings.