MelmothW,
The SNP claim many powers but even their most ardent followers would not claim to be able to backdate Scottish independence to 1949, I just tried to 2nd guess what is to come.
The 1949 date is a function of the British Nationality Act 1948, which was updated by the 1981 Nationality Act. As I said before it is up to UK Government discretion as to what goes in the UK Nationality Act in the event of a Yes vote. Personally, I would expect that UK resident Scots will be able to chose if they wish to remain UK citizens. For those, North of the border I see no reason that it should follow the Eire model, do you?