Larry, thanks for the additional info. I also speculated whether or not Lionel  may have built it at the factory.
I will  try to find out more about the history, but i am trying to  stay with conventional wisdom about the year 1952.
Since i was also born that  year.

Regards, Mike

I recently purchased a Lionel 2345 AA Western Pacific set from 1952, and   noticed the horn was in the non powered unit, and was  not working so during my research on goggle, i am seeing  that  the horn was supposed to me in the powered unit, but i am not  sure. So my question is, did Lionel put the horn in the powered or non powered unit of the 2345 WP in 1952, or do i have a bastardized set. If not then what chassis do i have. The powered unit has the two horizontally mounted engines and  the eunit. The non powered unit has the horn and pickups. Also, i am reading that maybe the pickups of the powered unit may be a different size from subsequent locomotives i.e. 2353. 

Thanks...