HO Guage Southern Pacific Daylight Baggage and RPO Cars

I think these are Athearn but I am not sure. Anyway I picked up a group of Southern Pacific Daylight passenger cars. Daylight was the name of the train, it possibly ran at night but you wouldn't want to miss anything. It ran along the coast between Los Angeles and San Francisco.
Anyway the first car here is the baggage car. The baggage car ran closest to the locomotives due to the smoke and smell. This was even after the cars were sealed and had no opening windows as it was climate controlled. I think thise started in the late 1930s. The next car is the RPO or railway post office. This could also be a combination cars which had an RPO and a coach section. That car went behind the baggage car.
Looks like a wide variety of locomotives for this. I am thinking either a pair of ALCO PA units or 4-6-2 Pacific.