Hi All
BCameron, just some notes from my own personal experience. My husband and me were both born abroad to British parents. Both our fathers happened to be working abroad for a number of years. UK visa and immigration rules have changed enormously over the years. You are right, you do need to give much more detail to your right to UK visas and nationality than you ever have before. This includes details on grandparents as the requirements now go further back up the ancestry line.
When I applied for my children's first passports, details on grandparents (maternal and paternal) were required including place of birth. Where you have a surname like Cameron, it can be hard to pinpoint details. However, lots of info has already been mentioned here:
You have the Gorbal births including the one for a John in 1934 (the reference to the Janet Seath Cameron birth in 1930 there makes this a possibity). You have an exact birth date for him in 1934 which is a big help.
Jamjar mentioned above the precise reference for you grandfather John's marriage to Patricia Falon.
in 1955.
You have your father's birth cert which gives confirmation of his parents' marriage.
I would say you have enough there to state your details on him on a form. Regardless of what you put down on the form, it will always have to be verified independently by authorities. They won't just take what you put down on the form as fact. You will be able to give them the details so that they can use these to view official records at the Scottish General Register Office -
www.nrscotland.gov.uk This is standard practice really.
If you do want to trace your father's genealogy back, then do work through the details on your Cameron/Falon grandparents. Finding John Cameron's parents' names from that 1955 marriage will let you work back to that marriage and family details etc...
Monica