The caption under the picture of H.R.H. the Queen Mother is wrong. She is not with Sir William Lyons, but with Roland Fox, then the managing director of VandenPlas. The article also mentions that in 1972 a DS420 was prepared for her, but this happened in 1970. The phrase "a car she kept until her death recently" should be interpreted such that she indeed used the DS420 model until her death, but there were several consecutive cars.