Hello Ian
Like you not having much luck.
But the marriage certificate does say St Charles the Maytr which is in Plymouth.
2 of the witnesses Benjamin and Mary Call are living there.
1841 Vauxhall St ST Charles the Maytr Prince George Pub
Benjamin Call 55 innkeeper y
Ann 55 y
Benjamin 20 tanner j y
Mary 25 barmaid y
Elizabeth Elliot 20 Female servant y
Susan Createe 15 same y
William Ryecant 20 Independent I or S
William Ginch 40 merchant y
William Phillips 45 ostler N
Mary 35 N
Elizabeth 20 N
John 20 plasterer jy
Louisa 15 y
Francis 14 plasterer j y
Richard 13 plasterer j y
Mary 9
William 1
As you can see it seems quite a big place.Could William Lumsden have been staying there? If the Calls filled in the form early ,they may have included who was staying at the time rather than on the 6th of June.If not is there some other connection to the Calls? If not why are they 2 of the 3 witnesses?
Photo of Inn here
https://www.closedpubs.co.uk/devon/plymouth_princegeorge2.htmlJames Street is quite a distance away so it doesn't make sense for Emma Catherine Strong to ask them.Why not ask her parents?
Ordinance Survey map 1856
Vauxhall street is by the docks ,running vertically from How Street by the Vauxhall Brewery
https://maps.nls.uk/view/128598089In 1851 the Calls are still the Innkeepers and now they have a lot of Sea Captains staying .There are 16 lodgers ,mostly master mariners and fisherman. Benjamin had owned the Inn since 1821 and was entitled to vote.
Does that help?
Ciderdrinker