Hi Denise,
I have found a christening record and census record on 'family search' which I think are for your John Thompson.
The christening record was on 27 Jun 1842, parents John and Emma Thompson at St Phillip Birmingham.
The 1851 census record of Moland St Birmingham has John Thompson b.1843 Bormingham, father John Thompson b.1802 Birmingham (gun stocker), mother Emma b.1804 Birmingham, brother Alfred b. 1829 (gun stocker), sister Amelia b.1836 Birmingham, sister Betsy b.1845 Birmingham, brother Henry b.1847 Birmingham.
regards, David