Hi Colin

I think you have a problem , maybe they never married, but why would Frances Marion give a married name at the second wedding ?
Looked on UKFreeBmd for all of Lancashire for any Frances/Francis/Marion/Marian for 2 years prior to 1911, nothing looked anything like Shimmin.
Also looked for any Shimmin, nothing anything like Frances
Also looked for any Robert or Richard and nothing looked like yours.
UK Census Online Free has him as Clarde in 1911 aged 42 , as a "Physican Lustenctor"
Assume they had no children ?
There was a marriage in Peel 1906 of Frances Shimmin to Thomas Corkhill , can't find a death for Thomas or another marriage for a Frances Corkhill.
Another possibility was she still married to Thomas , so could not marry Robert ??
Tried "Lancashire Online Parish Search' , but no marriage, also Robert's death is not there, and to them, the place name of "Stanley" does not exist.
As well looked on the free site "Old Mersey Times" has incomplete Birth, Marriage, Death and Inquest notifications , and no luck.
The Manx Library has newspaper notices (You have to Pay, not here in Aus) of the Peel City Guardian of 1/4/1911 of the death of Mr Phillip Shimmin of Stanley Rd , aged 84, and 16/5/1931 of Catherine C Shimmin of 13 Stanley Rd aged 84.
Not sure what the notice might tell you , but it may well be worth a look.
This is the third person in a row that I (And others) have failed to find what they want , I might have to retire !!
Cheers
David Dwyer