How certain is this dating of Robert Elwood's death to 1833? In the account of JBS' last days by his daughter, there is an entry as follows:

March 8th. [1897] Began his paper on 'As is the Heavenly', -- said he did not think his time here could be long -- talked of this day 33 years ago -- of Abney Park, Mr. G. V. Wigram, at Mr. Elwood's grave side, 'Death is ours'.

This would date Robert Elwood's death (assuming it is the same person) to 1864?

Thanks, that sounds credible. So it seems Robert Elwood certainly did not die in 1833.

James Butler Stoney, his wife Mary Francis Elwood, and daughter Anna Maria Elizabeth Stoney are buried in the Dean Road Cemetery, Scarborough, England.
The "what3words" address of their grave is: ///shakes.chin.sake