Sometimes it is hard to trace people born from the middle of 1900's forward than it is to find the genealogy of same.
The british telephone book is on line, there are only 7
listings for the surname Dudley, all but 2 live right in Belfast. Telephone numbers, full address and postal codes
are listed. Provide the information you have posted in a letter and ask if there is any relationship.
There are over 100 Turners so you would need to pick out a few from the 25 the Belfast addresses.