I do not remember what Series 1 diesel had, but my early 2a diesel had the key switch under the instrument panel next to the engine stop, but the headlight switch did not have a key in it. While it is possible that very early diesels retained the same switch as the petrol, I think it more likely that the instrument panel picture is an incompletely changed copy of the petrol one. I do not have a Series 1 parts or workshop manual, but these should clarify it. In the Series 1 the bellhousing is different as the petrol bell housing has to fit the 2.0 petrol engine, different from the diesel and the 2.25, but the Series 1 2.0 diesel engine has the same bell housing as the Series 2 & 2a petrol and diesel. The Series 2a six has the same bell housing as the Series 1 petrol.
John

