Kurt,
I just looked up the Santa Fe switchers in my Iron Horses Of The Santa Fe Trail book. They are not specifically identified as Sw9s, but the 2418 class is identified as being 1200 hp EMD switchers. The first four numbers in the class are identified as "cow & calf" sets, known as TR-4's. I presume TR is the designation of transfer locomotives. The numbers on them were 2418 & 2418a, and 2419 & 2419a. If I'm interpreting them correctly then #2420-2438 were all aquired in 1953. #2439, 2440, & 2441 were rebuilt to Sw9 standards from 900 hp winton powered switchers built in 1937. I don't have any pictures of those units prior to rebuild, but the rebuilt #2441 looks identical to #2425 & #2438. On all of these units, the zebra chevrons point up in front. I don't have a rear view, but it would appear that they point down in back. There is a single horizontal stripe running from front to rear at the hand rail on the long hood with A. T. & S. F. above the handrail.
The radiator is mouted on the front of the nose and is not striped, but the top part of the frame around the radiator is painted silver from the continuation of the stripe at the hand rail over the top to the continuation of the stripe on the other side. There is a dual headlight mounted vertically above the radiator with number boards coming off both sides. On the left side of the locomotive about at the halfway point above the front truck is a ladder of grab irons going up the side of the hood. Right behind this ladder is the square logo with the circle cross inside it. Interestingly in the picture of 2425 the lettering above the handrail says A. T. S. F., the "&" is missing. The circle/cross in a square logo is mounted directly under the spot where the "&" would have been. On #2438 the "&" is where it should be and the logo is centered under the "&". The airhorns of both units appear to be single horns and are mounted to the front of the cab right under the roof at the center peak.On #2425 the stacks appear to be topped with screen wire spark arrestors. #2438 appears to have no spark arresters. In both cases the bell is mounted on the roof directly in front of the front stack. The distance from the stack to the bell appears to be about the same as one letter plus (.) in the A.T. & S.F. sign. The zebra stripes on the cab start at the top of the long strip in the long hood and wrap around the cab from where the front of the cab joins the long hood.
I hope this helps you with your modeling, Kurt. If you have anymore questions, post them and I'll try to see if I can find answers.
Russ