Gary Lee shot a couple of videos of the Pan Am Railways (ex-Guilford) unit in St. Stephen. Pan Am has an isolated piece of track from Calais that serves the Woodland, Maine mill. They interchange with NB Southern in Milltown at the border. Occasionally you can see the Guilford unit in McAdam as it gets shipped out for servicing by Pan Am. I saw MEC 320 in McAdam on November 25, 2006.
Here are Gary's videos.