Plaque: Edwards VI and VII
Erection date: 16/10/1905
Edward the Seventh, King of Great Britain and Ireland and the British Dominions beyond the seas, Emperor of India, laid this stone of King Edward's Building of the General Post Office on the 16th day of October 1905 upon the site of Christ's Hospital, founded in 1552 by King Edward VI.
At the time gilded lettering incised into granite was a popular technique. We can't say what it was like when new but its legibility has not improved with age.
Site: Rowland Hill statue and 2 Edwards (2 memorials)
EC1, King Edward Street
The statue was first erected in front of the Royal Exchange, about where Peabody now is. Spitalfields Life have a photo of it there c.1910 with the Royal Exchange on the left (though captioned as King Edward Street). It was moved to King Edward Street in 1923.
The plaque is on the wall that you can see between the statue and the phone box.