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26 April 1834
Sarah Blake late of the Parish of Saint Clement Danes but since living at Clapton in the County of Middlesex will proved at London. A cup and cover presented to Sarah's lamented husband by the Pewterers Company was bequeathed to her eldest son John William as long as he defrayed all expenses due upon the said cup and cover within twelve months. Reference: TNA PROB 11/1829/465

This very neatly confirms that John William Blake (Grimwade p. 442, 738) was, as Grimwade suggestes, the son of Sarah and her husband John Blake (Grimwade 442, 737).
The mark of Sarah and John William entered in 1809 (Grimwade No 2483) was that of the widow of John Blake and his son John William Blake.