Just got the Super Chief set for my son for Christmas.  The Sante Fe engine was missing the rear coupler right out of the box.  In fact, there was not even a part for the coupler to come out of.  It looks like something broke off.  What can I do about this without lengthy packaging, mailing, and feeling like more shipping damage can occur?  BTW, I checked the schematic online, and the drawing does not clearly reveal the parts I need.  The parts don't look like they go on the rear of the train.  VERY CONFUSED.  Also, why is there a general lack of documentation for these sets?  regards to all who reply.