Hi Kev,
I now believe that we have 2 different families, although they are quite possibly related as records tie both families to the areas of Broadclyst and Exeter in Devon, the census from 1861 in Hull shows your Thomas age 28 a Fisherman with wife Mary age 27 and daughter Mary age 5 and Brother William age 25 a Fisherman, my William brother of Thomas had immigrated to Adelaide, Australia with his mother Elizabeth nee Page and brother Francis on the ship Sibella in 1852, at this time the father William Blackmore had passed on, he died on 1st May 1841 after a recently built chimney collapsed and broke his back on a building site at Fore-Street Hill, Exeter premises of a Mr Nicholas Tucket.