Nice find on the marriage, Andrea - I didn't think of inverting the forenames.

!
I'm still looking for Walter in 1891; the 1881 census is available online free at
http://www.familysearch.org.
Here's Walter as a baby on the 1871 census:
RG10/1060/85/8 - Jenkins Croft, ArdinglyRichard Simmonds Head 45 Sawyer
Mary Ann Simmonds Wife 44
Thomas Simmonds Son 22 Bricklayer
George Simmonds Son 20 Sawyer
Joseph Simmonds Son 18 Labourer
Henry Simmonds Son 16 Labourer
Alfred Simmonds Son 14 Labourer
Joseph Simmonds Son 12 Scholar
Ann Elizabeth Simmonds Dau 10 Scholar
Morris Simmonds Son 7 Scholar
Alice Simmonds Dau 4 Scholar
Walter Simmonds Son 5m
All born Ardingly.
The IGI (available free at the same site as the 1881 census) has a possible birth for Richard Simmons on 7 Dec 1826: parents James Simmons and Philadelphia.
Trying to see if Richard and Mary Ann's marriage is on Free BMD, but they're updating their hardware at the moment, and the site isn't performing as well as usual - I'm just getting error messages, so will try again later.
Rambler