If we're going down memory lane (but not to hijack a thread about price), here's the only Pioneer Zephyr I know (aside from Lionel's earlier chrome plated version), from the Museum of Science & Industry, Chicago:
Note that the "brow" is not as pronounced as on the model - also it appears to be standing on Fastrak!
And there's this nice Burlington brochure of the Mark Twain Zephyr's route:
