John: To add to my earlier reply, Colonel Duff died April 16, 1900 in Richmond Borough, London. The London Sunday Times, April 22, 1900, in an ad, says he died at "Hazeldene, Castelnau, Barnes." I assume the Castelnau St., Hazeldene and Barnes mentioned are the ones in Richmond Borough. His probate was Oct. 27, 1900 leaving an estate of 7064 pounds to his widow, Harriet Paul Duff. Harriet was living in Bath, UK in 1911, with their daughter Julie Duff Taylor.
I would think that the death certificate of Col. Duff would indicate the place of burial. I only have online access to the indexes for death certs and probates, not the actual certificates.