There's a lot less time and expense to attach a coupler pocket to a car body instead of going through all of the complicated stuff shown above. You just drill mounting holes and screw it in, or you can attach it with contact cement if that's inconvenient, such as on cast zamac metal car floors, although such floors appear to have gone away back in the Jurassic.
Truck mounted couplers are guaranteed to give you bad operation if you back your train up much at all through switches. On long unit trains rolling continuously forward that the OP appears to have, it might not matter much. But with any kind of backup moves, which real railroads do all the time, truck mounted couplers push the truck to one side, the flanges are guaranteed to pick at and catch every possible molecule anywhere that could possibly derail a car.
I learned all of this 50 years ago as a young modeler beginning to get beyond loop operation and into switching, who still had a few cars from the original train set rolling on the layout. Once in a while, I will buy some "heritage" car from the distant modeling past on eBay. The first thing that happens on arrival is that those Talgo trucks come off and get replaced with state of the art trucks with metal RP25 or better flange wheels, and body mounted couplers. Those toy train trucks invariably have wheels with pizza cutter toy train flanges on the wheels that, coupled with the sideways back up pressure, will put your train on the ground every time. And half the time the holes in the journals are not shaped properly to accept contemporary wheels.
Truck mounted couplers are guaranteed to give you bad operation if you back your train up much at all through switches. On long unit trains rolling continuously forward that the OP appears to have, it might not matter much. But with any kind of backup moves, which real railroads do all the time, truck mounted couplers push the truck to one side, the flanges are guaranteed to pick at and catch every possible molecule anywhere that could possibly derail a car.
I learned all of this 50 years ago as a young modeler beginning to get beyond loop operation and into switching, who still had a few cars from the original train set rolling on the layout. Once in a while, I will buy some "heritage" car from the distant modeling past on eBay. The first thing that happens on arrival is that those Talgo trucks come off and get replaced with state of the art trucks with metal RP25 or better flange wheels, and body mounted couplers. Those toy train trucks invariably have wheels with pizza cutter toy train flanges on the wheels that, coupled with the sideways back up pressure, will put your train on the ground every time. And half the time the holes in the journals are not shaped properly to accept contemporary wheels.