Would you mind if I direct a question at you? Since you've been there...
I've been torn on whether or not to tell my son about his father, he isn't born yet but I know this is an issue I should face.
When would you have preferred to know? =/
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On topic with yours, I'm afraid I have no idea of a cheaper route to take. Have you considered going to that area of England and ask around? You'd be amazed at the people who might remember that couple's name or the people themselves and could give you clues/ideas.

- And it'd be more fun!