Doodlebugs/Gas Electrics

["Larry Doub" <nftrains@n...>]

Hello Every Body,
First,I wish to wish to be the first to wish you all a HAPPY 
THANKGIVING.
Second,
I'm Planning on adding a EMC GAS ELECTIC DOODLEBUG to my
collection for my layout,
What was the reason for building these and just how were they used?
They are a combined passenger/mail car right?

Larry