I've been looking around at all the censuses and records to see if I came up with anything else but no.
Observations,
The Richard in the lunatic asylum has poor house records starting in 1891, born c1876 Bromley with a father Richard deceased, records in 1904 again claiming monies for his upkeep, mother Mary in workhouse so not the one who marries Susan Clarke Claridge in 1898.
Susan in 1911 says married but like you can't find Richard and can't see a suitable death. Of course she and Richard could have parted company and she is saying married to keep up appearances. This could be Susan's death, area is good and the age matches up with date of birth. Not that it helps in finding Richard

Deaths Jun 1/4 1944
Susan C Fitzgerald age 69 Islington 1b/227
The Richard with Susan in 1901 is not the Richard born Waterford and a sheep dealer in Middlesex 1901 (and single) who is in Lancashire in 1911 with wife Margaret still a cattle and sheep dealer.
When ordering a certificate you could specify that the groom's father has to be Richard (if you are certain of that).