Clearly there is some overlap between the records of the Swan Tavern & the Swan Tavern Tap, if indeed they were separate pubs.
I think it is likely that there was one Swan and a separate Globe. King William Street did not exist before 1820. **
St Magnus Martyr pub history index
A listing of historical London public houses, Taverns, Inns, Beer Houses and Hotels in St Magnus Martyr parish, City of London.
Residents at this address
1856/Mrs Ann Chislett/../../../Post Office Directory
1861/Henry Chislett/Victualler/42/Somerset/Census
1861/Ann Chislett/Wife/48/London City, Middlesex/Census
1861/Elizabeth F Chislett/Daughter/6/London City, Middlesex/Census
1861/Ellen Geand/Domestic Servant/20/London City, Middlesex/Census
1861/Jane Smith/Servant/28/Witney, Oxfordshire/Census
1869/H Chislett/../../../Post Office Directory
1871/Not inhabited at night////Census
1881/Henry Chislett/Publican, Widow/63/Milborne Port, Somerset/Census
1881/Ann Chislett/Wife/69/Horsleydown, Surrey/Census
1881/Bessie Chislett/Daughter/25/London City, Middlesex/Census
1881/Annie Dachtler/Domestic Servant/19/Bermondsey, Surrey/Census
1881/Elias Walter/Boarder, Landscape Gardener & Contractor/68/Peckham, Surrey/Census
1881/William Hole/Boarder, Fishmonger/58/Hythe, Kent/Census
1882/Henry Chislett/../../../Post Office Directory *
1884/Henry Chislett/../../../Post Office Directory
1891/Henry Jared/../../../Post Office Directory
1895/Henry Jared/../../../Post Office Directory
1899/Arthur Jared/../../../Post Office Directory
1910/William James Hammerton/../../../Post Office Directory
* Provided By Ewan
** Provided By Stephen Harris