How this sound. The first idea was to select the cards and then use them in a reverse order to the main, that is, you would first pick up cars at the locations your will deliver to, take them to Elsewhere and then get the cars to deliver, not the ones you just delivered. Confusing and you would always run the same cars both ways.
What if you select cards. Say you have 1 box car for the pier, 2 hoppers for the coal dock, and 2 flat cars for the saw and a passenger car. You pick up the cars at Ortona from yesterday's freight and a passenger car. Deliver yesterday's cars to Elsewhere, stopping at all passenger stations on the way. Turn your engine after setting out the cars and make up the return freight. You would leave Elsewhere with 1 box car, 2 hoppers, 2 flats and your passenger car. Stop at all mainline station on the way to Miller. drop 2 flats at the sawmill, and pick up the cars there, say 3 flats. Then drop 2 hoppers at the coal dock and pick up the cars there, say 1 hopper. Proceed to Northdale stop at the station and deliver the box car to the pier, picking up the cars there, say a box car and a flat car. Return to Ortona dropping the passenger car, 4 flat cars, 1 hopper, and a box car. So now there are 6 freight cars for the next train to take to Elsewhere. This is more like the mainline trains and the consist will be different both ways.