Bound Diocesan records for the period 1877 to 1914 are held at the ‘Hertfordshire Archives and Local Studies’ at the County Council offices in Hertford. Whilst searching for information on Blackmore, I came across the following information relating to the High Country parishes.
Rural Dean. Lambourne.  8 March. The Bishop appointed Lewis Newcomes Prance Clerk MA Rector of the Rectory of Stapleford Tawney with Theydon Mount in the County of Essex and Diocese of St Albans to Rural Dean of the Rural Deanery of Lambourne in place of Cavendish Harvey Foster Baronet Clerk BA resigned [HALS DSA 1/14/1. Bishops Act Book 1877 – 1890. f182].