Welcome, Wombatz, I hadn't realised you were a newbie. We are here to help.
I did a trawl thro' the complete GRO birth entries1953-1962 without finding any siblings for Christopher, I then went on to look at the marriages 1972=1981 found the following.
Christopher Tungate = Gillian M. Bell
Dec ¼ 1980 Norwich 10 1452
Probably not the district you would have expected but it may be the reason you have not found anything for the family in Shropshire. A sight if this cert will tell you if it is your Christopher as father's name will be shown. Again an address should be shown that could be a help in a search, like 'phone books. For instance, in Aug 1981 there are 39 Tungates listed in the 'phone book for Norfolk of whom 19 are in Norwich.
Good hunting,
Meliora