Hi Carole,
Checked Freebmd and plenty of David Lewis' but no birth records for David Aubrey Lewis coming up.
There are two ladies listed on the same page for the marriage record.
If I have found the correct headstone (which again only states David Lewis, Travellers Well, of this place), then his wife would have been Mary Jenkins before they were married in the first quarter of 1891.
All I currently have is circumstantial evidence that I have the correct headstone, but if it is correct, then the person was born on April 29, 1855.