Does anyone know how many Amtrak Material Handling Cars are still in existence? Also, does anyone know of any that might be available for sale or donation?

If their website is up to date, you might want to try these guys:

http://www.railmerchants.net/amtrak-material-handling/index.html

That can't be current, can it? Besides the 2007 copyright date, is the Mark Twain Zephyr still for sale? WSOR E9's for sale (leaving the matter of the E9B rebuild aside)? I would say this is all very out of date.

We've talked about these before but I think they were built from trucks and other parts from the old REA fleet. I always liked seeing these cars on the old mail train on the corridor.