Forget what I said about the change of wife, the will and codicil are both written in Nov 1842, will proved 1853. I misread the relationship given in relation to Ann.
GRO death 1853, Audley Mucklow aged 63, birth therefore c1790.
Death of Mary Mucklow aged 69 at Leadenham buried 30 Dec 1860.
The Audley MUXLOE (widower of Dembleby, Lincs, farmer and grazier) to Mary SWANN by license 31 Aug 1828 at St Peter, Saxby, Leicestershire marriage looks good. In 1851 Mary is born Stonesby, Leicestershire.
Based on the c1790 birth of Audley and Robert, Edward and Ann siblings in the will I'm looking for baptisms around the same period and found four at Leadenham all to an Audley and Elizabeth
Ann 1788
Ann 1793
Edward 1794
Robert 1797
Having looked at the Leadenham Register Images on FindMyPast it's apparent 1791 and 1792 are very faint and Freereg baptism transcriptions for those years are missing. 1793 is much clearer and there's a burial of an Edward, son of Audley and Eliz, I've almost convinced myself I can see his baptism in 1792 but it's so faint I could be seeing it because I want to.
I'm trying not to see the Audley Mucklow of Leadenham - Elizabeth Byron marriage at Buslingthorpe being the parents of the 1788-1797 baptisms, throw in a son Edward who died as an infant and using the faded 1791-1792 entries as an excuse for a missing Audley.
I think the 1821 will of Audley Mucklow of Long Leadenham is crucial now. Freereg burial 12th Jul 1820 as Audley Muxloe