I was considering buying a Fleischman Steam Locomotive, but I notice they come with " Automatic couplings". This would be my first purchase of anything other than U.S. so I’m not sure what this is exactly. Would I be able to use any of my existing cars that have Kadee couplings?
Probably not. The European coupler on most models is called a NEM, and is not compatible with U.S. knuckle couplers. It may even be possible that the coupler can’t be changed because no Kadee or other brand would fit.
This is a Roco but you get the idea. I just attached a KD to the original with hot glue and wire at the right height. As you can see it looks quite peculiar and makes for a big gap between the engine and a car.