« Reply #10 on: Tuesday 04 June 13 15:38 BST (UK) »
the only way to be sure is to go one step at a time and it can be dangerous to assume ages at marriage or at birth of a child. You need to use certs in conjunction with census entries. The 1881 & 1891 census entries show that William senior was about 33 when your grandfather was born. The birth cert for Lydia should give Elizabeth's maiden name so that you can then identify the marriage for William & Elizabeth. Without knowing her surname, there are too many registered Swansea to be sure which is their marriage. From their marriage cert, you should find the name & occupation of your greatgrandfather's father. Without that cert, there's no way of knowing if his father is James the boatman or William the ag lab or someone else not yet indentified.
Cornwall: Allen, Bevan, Bosisto, Carnpezzack, Donithorn, Huddy, James, Retallack, Russell, Vincent, Yeoman
Cards: Thomas (Llanbadarn Fawr)
Glam: Bowler, Cram, Galloway, James, Thomas, Watkins
Lincs: Coupland, Cram
Mon: Cram, Gwyn, John, Philpot, Smart, Watkins
Pembs: Edwards (St. Dogmael's)
Yorks: Airey, Bowler, Elliott, Hare, Hewitt, Kellett, Kemp, Stephenson, Tebb