Hi,
Harold and Annie married in 1887 (West Derby, Sept Qtr, Ref 8a/584) and in the 1901 census they were living at 7 The Grove, Lower Bebington. Wirral.
Harold was 41, Annie age 32 - no children present. I have found a tree that also suggests they had no children.
Gwynedd Family History Society has various publications for sale (which include memorial inscriptions) and they may help you to find the grave.
Alan