I'm building a GRS kit of a class 121 DMU. While checking photos in Kevin Robertson's book on first generation DMU's, I found a picture of a class 121 hauling an LMS full brake, The caption states this was a Maidenhead to Aylesbury working, in 1961. Does anyone know if this was a regular occurence? Could bubblecars be found hauling similar stock on other routes? From post 18 I expanded this thread to include photos, sightings, operational instructions etc, anything covering any DMUs and GWR or other railcars being used to haul other stock, especially non-passenger stock.