If you have any tips for us in planning a trip to Dunfermline that could unravel some of this mystery we'd appreciate it.
Do as much research as you possibly can online at
www.scotlandspeople.gov.uk before you set out. This means (a) that you won't waste scarce time in Scotland finding stuff you could have found before leaving home and (b) you will have time to organise and assimiliate it so that you know exactly what you want to find out when you arrive.
Most of the principal primary records (BMDs and census) are in Edinburgh, so don't go to Dunfermline expecting to find them there. Make sure that you know exactly what you will be able to find in Dunfermline before you go there. Contact (join?) the Fife family history society and get their advice on what sources exist that might tell you what you want to know.
And don't even think about considering the idea of driving in Edinburgh. It's difficult to move, hard to find you way around, impossible to stop and very expensive to park, if you can find a space at all. Use the excellent public transport system instead, and save some cash by not hiring a car until you are ready to leave Edinburgh.