BJB,
Just out of interest, do you know if either of the witnesses of Samuel's marriage are connected to him? Could one of the witnesses be a brother or an already married sister? I know its a very long shot, especially if he married away from home, but I managed to find a branch of my family by researching the witnesses.
Do you know if Samuel served in the First World War or which regiment he may have served with?? That seems like your best bet at the moment for finding him, though from what you say it sounds as though you have already searched and searched for that information.
I seem to be in the same boat as you at the moment, I have a rellie's marriage cert, date of death and father's name, but because I don't know where she was born, I can't find her anywhere! Frustrating isn't it!! I wish they could have put "place of birth" on a marriage certificate, it would have been so useful!!

Best wishes,
millerina