LGB model train spare parts can be quite expensive, especially if you want to build your own waggons and need a lot of them.
I redesigned the original coupling mechanism, including a softer and a harder spring, to be printed by yourself. I have uploaded all .stl files and a single .3mf file including all parts with paint on supports already placed where needed.
I recommend printing the spring from PETG because of its higher toughness compared to PLA. For the other parts PLA will work just fine.
To fit the secure clip you can simply use an M2 screw. The hole should already be large enough to fit it without drilling it to size.
The author marked this model as their own original creation.