Hello Annie,
I have Ann's death certificate, and as you guessed, she died at Eastwood in 1866 age 60, and Thomas was present. I suppose it is feasible that Thomas was married earlier on, as on the 1841 census there were a Charlotte (age 15) and Martha (12). Thomas would have been around 20 when Charlotte was born. ("my" Ann would have been around 15) I didn't find the two girls in parish records, but all the others were, so I considered they were just "taken in" by T and A. After this census it is difficult to track them.
T and A's sons Thomas, John and George all became blacksmiths. Their son William was an errand boy in 1851.(age 12) (Must be a different William you found.)
I spent some time exploring the Oakleys and Oxleys, and there are some vagues hints they are connected. Thomas himself died in 1874 age 69, at his son's (George) in Lichfield.
If Ann's maiden name WAS Carrott, can you think of a reason Thomas as a blacksmith, would have been living in Barrowby when they were married at Langford in 1827? (eg. Are there old mines around there?) Thank you very much for helping. Diana