I agree with rosie99 - the marriage certificate is essential

With common names, like Watkins in Wales, you need all the clues you can get.
Marriage Certificates will maybe give you ages of bride & groom, names of fathers and their occupations, and groom's occupation.
Then it's over to 1939 National Register and/or censuses.
1939 National Register has a Leslie Watkins, born 1937, in Alexandra Road, Abertillery?
He's with a Rees Watkins and 6 others.
Potential marriage:
March qtr 1926
Bedwellty Registration District vol 11a, page 179
Watkins, Rees
Hunt, Ruth