I used Flickr to host my photos shown at the thread start. Some discussion ensued about blue plaques not usually being for people who are still alive...
Yes, I undrstood that to be the case, David. But as one of the comments on Flickr says, there are blue plaques other than those provided by English Heritage, and the Jackie Stewart one was installed by the local authority.
From the English Heritage website:
The criteria of the scheme state that, in order to be eligible:
a figure must have been dead for twenty years, or have passed the centenary of their birth, whichever is the earlier.
a building associated with the figure must survive in London.
proposals will be considered for the commemoration of sites of special historical interest (for instance, where a key event took place), but these should be shown to be of national significance.