Hi - No, I didn't look at manxbmd. I gave you the URLs of all the sources I mentioned, so that you could double-check those. I think they were more likely to have married (or not) before going to the IOM, which is why I suggested looking at www.freebmd.org.uk. If you find his previous wife's death there (do you have this?) it will cut down the marriage possibilities.
However I do think it is a good idea to look at manxbmd to see whether Maud married in the IOM. It is possible that the Maud aged 21 in the IOM is the same Maude who was William Henry's daur aged 13 in 1891. She was b.March quarter 1878 in Plymouth 5b 285 (birth regt for Maude Nellie H Cox on FreeBMD).

Sue