Hello Karen,
Regarding your search for John (jack) hayward, there was a birth for a John Hayward registered in Pontypridd in the Apr-May-Jun quarter of 1905. If his parents were living in Llanbradach at the time this would have been in the registration district of Pontypridd.
This ties in with an entry on the 1911 census, this shows that living at 2 Heathview Road, Thornton Heath as lodgers were;
Emmanuel Hayward, age 29 a bricklayer born in Marnhull, his wife Eliza Hayward and more inportantly their nephew John Hayward born in 1906 in Pontypridd. Census returns are often inaccurate when giving exact ages.
Of course there is also a link with the fact that he died in Leatherhead which is in the same county as Thornton Heath, namely Surry, and is not a million miles away.
I hope this points you in the right direction in your research.
Best Wishes,
Tallpaul.