Will it collect the milk tanks ready in the yard before heading for Plymouth and then onwards to London?

Alex Seal says I believe milk from Saltash was forwarded to Plymouth North Road on the rear of the Saltash Auto Trains. You can also see from the Banner Repeater as well that Saltash's Up Main Starter is off as well. But Andrew Vines says " The up milk was timetabled to collect the loaded tanks from Saltash in the 1960s. The down empties appear to have been delivered from Plymouth by a light engine or a local train, possibly because the track layout was more awkward for stabling the tanks in this direction".