I know this isn't standard gauge but it is defintely prewar; check out the link above. It is to the Chicago Museum of Science Pioneer Zephyr page. They (the museum) put together a really nice website detailing the Zephyr. Check out some of the odd facts on the site like the menus:
Fried Egg Sandwich
Very interesting stuff. I wish someone would put together a standard gauge Zephyr. I saw one in G gauge and it was really nice (By Roberts Lines I think).
By the way, the Flying Yankee also has a fantastic website:
It is absolutely worth a vist for both. I hope the public gains some awareness about these two marvelous achievements. These two trains have a style and flare that are distinct in our culture. Someone please make them in standard gauge (it should have been done by Lionel in the 30's anyway!!!)