When I purchased my 1955 Slough Built Light 15 the negative terminal on the battery was connected to earth. All of the electrical diagrams I can find show the car as positive earth. Does anyone know if the later Slough built cars were negative earth? It is possible the car was converted to negative earth, but I’m not sure what would indicate that this had been done. It still has a dynamo, so hasn’t been uprated to an alternator. The car starts without any problems and has been running OK.