Spitfire Tours West Highland Tour
 

Having recently reviewed Spitfire Tours website, they are running a tour with a 20+37 to Fort Bill, Mallaig & Oban. Does anybody know if a Class 20 ever worked a Charter train on the West Highland Line? I do know they sometimes topped class 37s to get them to/from Eastfield. Did any ever work the whole length of the line in multiple with a 37?