This was Intercity charter unit stock for the Orcadian and Highlander, which included Mk.1 Pullman kitchen car 335. The others were 1672, 3045, 3096, 3098, 3100 and 17025.
http://www.flickr.com/photos/145367983@N08/49676831082
Locos trapped to the north of the collapse were initially 37414/15/16/17/19/21 and a reported 16 coaches. 156446/57/74/77/78 were moved north by road in March/April 1989, 37414/19 returned at the same time. 37415/16/17/21 returned to Inverness in October and were replaced by 37418/19/20. The charter stock, 6300 and other coaches also moved south at this point.