re: One thing to look for...
I would suspect that when the ammo dumps are searched, if any WMD-related items are found, it will be empty shells designed for WMD use, but not containing WMD substances. With the fast track scenario, the means of delivery would be produced earlier, but concealed, and ready for filling on short notice.
This also makes more sense than the idea of filled WMD shells stuck, unmarked, among regular shells. Even Saddam wouldn't do something that stupid.