Was the church St Anne's before 1884?
Yes.

"The present church, the third on the same site, is an excellent example of a simple Victorian building of stone, 90 feet long by 39 feet broad, with a beautiful reredos and mosaic of the Crucifixion. It was built in 1884, entirely by the generosity of Sir Robert Loder of Whittlebury Lodge, very near the time of his lavish restoration of Whittlebury church."
http://www.whittlewoodparishes.org.uk/silverstone.htmPevsner ... St Michael 1884.
SOG National Index of Parish Registers Vol 9 Pt2 Northamptonshire ...
Silverstone St Anne later St John (created 1831 from Greens Norton)
(Greens Norton Hundred; Towcester Union)
OR C 1831-1948, M 1832-1960, Banns 1832-1956, B 1831-1911 (NRO)
BT 1831-1872 (no 1866-69) (NRO) (Eighteenth century entries in records of Whittlebury)