Hi Liz

So if we assume that Catherine was a widow when she married Henry Boardman Sep Qtr 1840, we have to look for his death from about September 1837 ( John James Hunt's Bap. Cert. does not state if Thomas was still alive) to September Qtr 1840, on the UKBMD Free site there are 12 deaths of Thomas Hunt in Lancashire, no ages listed in that period.
Civil registration started in that Qtr (Sep 1837) so this is the 11 registrations and districts :

Jun 1838 Warrington
Sep 1838 Chorley and Liverpool
Dec 1838 Bolton
Jun 1839 Liverpool
Dec 1839 Wigan and Salford
Mar 1840 Bury
Jun 1840Prescot,Burnley&Bolton
Sep 1840 Ashton

Hope that someone may be able to help with the details of these deaths, particularly the two in Liverpool

Cheers
David