It seems to me an odd arrangement that two cylindrical items are touching each other at right angles - the guide roller pin and the retaining bolt. Is this likely to cause wear if they move against each other? The retaining bolt looks a bit awkward to get in, towards you from a blind position, though that shouldn't lead to the mistake of not fitting it properly.
Must be interference fit. Does only make sense, if loads are entirely carried by the stop plates and pins. I still haven't understood entirely how the stop pins and plates disengage. Are they installed with the same incline than the guide track, so that the entire plug moves out and upwards at the same time?