R = RF ammo +15
B = Belt right (any speed)
O = One way (edited in JCS.ini just as suggested in the article - has the new Speed parameter set as -127)

Now cover the tiles where R and O are with walls in layer 3 so it looks okay. The pickup will go along the belts and once it gets to the O tile, it will reappear back at the start. Covered with those walls, it will look like a line of boxes being transported somewhere.