Attached is the civil birth record for the William James Elwood that I'm researching (born 20 Jan 1885 in Cratfield, Suffolk, England). Mother is Harriet Elwood, no father named. That's what I'd assumed based on the 1891 census since he was living with grandfather James Elwood and James's single daughter Harriet, but it didn't overtly state that William was the child of Harriet, as opposed to one of James's other children. So this birth record confirms that William James Elwood was Harriet's illegitimate child. I hope it's useful to you as well.

For what it's worth, this is a collateral line for me (I'm not directly descended from James, Harriet, or William James Elwood), so I don't currently have much else on them besides birth dates and the names and birth info of James's wife and other children. I'm happy to share what I do have. Going back from the point where your husband's line and my line intersect I do have a fair bit of information. A lot of it is already online at FamilySearch.org and other places, so you might already have it. In case you don't know, the father of the James Elwood born in 1824 was also named James Elwood (born in 1796 in Cratfield, Suffolk, England, wife Keziah Bickus/Bickers born 1799 in Cratfield). Keziah Bickus/Bickers and James Elwood Sr are my great-great-great-great grandparents. If you'd like to see what I've got on that line, contact me at prufrock_j_a at hotmail.