Maybe it is just me, I am not a fan of that milk car. When they work they work great but when they don't it is difficult to impossible to get them work right. So it is probably me.
Your doors appear broken. The doors are held on a frame and two that tabs should be on the bottom. Yours are gone.
I do notice to operate the car the shell needs to be on because one of the sliding parts needs to bang against the back door to push the can out.
The cans should have a magnet and not just the plastic one.
Are you talking about this frame? If so, its different, plastic. 3472 is a steel frame. Looks like there is something hitting the frame, pushing the doors out. Nevertheless, the doors operate ok. Since this has metal doors is it a 49'?
I have a 3662 that I upgraded to command operation, and it works flawlessly. The nice thing about the command option is the ERR Mini Commander HC allows you to tune the drive to the solenoid to optimize the operation.
I had to dig deep and found two 3472's One had bad metal doors and got replaced with plastic, I took pictures of the metal one.. On mine the springs don't work well.
On the back side the door is jammed in on the left and you can see the part that hits it.
Some where between 49 and 53 they switched to plastic doors. This car has staple end trucks my other one has bar end. For operation I prefer the 3662
So mine has staple end trucks but not a coil coupler. I thought all stapled trucks had coiled couplers. Also, what prevents the containers from falling into the gap between the platform. The slinging device is aluminum, right hence the container wont stick to it. Its thrown to the platforum.
The Tandem site for ID Lionel Trains will tell you. There was still an earlier version. Maybe that one had coil couplers. Time wise they were phased out on rolling stock. Coil couplers are still found on engines. Maybe you need more power. They should fly out of the door.