Found a 1946 3854 Merchandise car I could afford. When I got it, I had to fix the wiring. When I took the boxcar apart I found this. One of the retainers for the end pieces was missing. One post was partially broken away. A replacement retainer would not work, even if I could find one.
After a couple of test prints I ended up with this 3d Printed retainer.
A little glue and the end is now assembled tightly. 
3D part make some repairs much easier.
