I recently met someone in Toronto who is modelling working couplers that function with either a home made magnetic wand or small rare earth magnets set between the rails. The pocket is made from brass rectangular tube & the pin is pivoted steel wire with counterweight that enters the pocket from below to trap the link. The only downside seems to be the link stays with the A end of each car while the magnetically operated pin is only on the B end of the car. Thus car ends are not universal connection.
The only other option I can see to make the car ends universal like a knuckle coupler is to install magnetically operated pins on both ends of the car & use tweezers or a magnetic wand to hold the link between cars for coupling cars where no link has been left in one of the cars.
