By the way, The 1203 was the third diesel built for domestic use with six powered axles.
The earlier two units were big transfer-service power built by GE for the Illinois Central. These experimental units were each equipped with different diesel engines when built in 1936 and they were scrapped in 1947.
In between there were a large number of ALCo built 6-axle diesels built for the US military during WWII and sent overseas to aid the war effort. These are not counted as domestic production by most writers.
Brian Norden