Oh, wow, just woke up to see all of this. Thank you both so much!
Now to unpick it all.

Are you suggesting that Thomas Carr was possibly Thomas Carr Irvine and that his father was JS Irvine not Carr? Plus, his mother looks to be Ann Rawsthorne? So he's dropped the Irvine for some reason.
And Catherine Lambert/Lombard might have been her maiden name and she made up
borrowed Irvine as a cover for something?
It all sounds a bit shifty - why the late marriage, why is Kate from Ireland in one census and why the "false" names on the banns? If she was married to someone else but living with Thomas, the Lambert butcher father doesn't fit.
Thanks for all of your help on this, it's been fascinating to read.
So, to look for Mary Ellen's ancestors I should look for Irvines and Lamberts really?