Hello Cousin, I'm glad you posted too!
I've been digging around on Ances**y since I saw your original query and found William b 1809, your John b 1816 and another brother James b 1813 in the 1841 census. All involved in coach making in Salford,Greengate and Salford, Deansgate. You might have already found these but John is named as Walton, the other two are Wetton. Nothing for George though and, well, Thomas is another story altogether.
William's wife is Maria (she of the witness to the wedding you mentioned perhaps?), I've found her as a widow in the 1851 in Deansgate on the page following Thomas Snr. in the 1851 which you might have already. She and the children are mis-transcribed as Smith including a son named Dorothia (Joseph b 1837) if that helps you seek it out
I've not made a firm connection between Thomas Snr's family one and family two other than Thomas himself and his widowed state at marriage number 2. And the constant proximity on census records. I have however seen him in another tree on that site with parents and many more siblings named. Family #1 isn't acknowledged only family#2 with Sarah Boulsover. I'm still checking it out.
There is a baptism for Thos Wetton in Ashbourne in 1788 to William and Mary if you like the look of it, I'd be interested in what you can make of father's occupation (I see coach but with this family I've been blinded by 'coach' anything)

That's more information and not many answers but it might be a mutual breakthrough.
Best wishes,Nelly.