Hi Neil, sorry for the late reply, I have been away for work ...
Yes, Alexander Morrison and Mary Stirling who married 26th November 1830 in Killearn were your Great, Great Grandparents (2G), they were my 3G Grandparents (do not buy the certs, I have all that are relevant and will share).
Alexander was the son of Andrew Mor(r)ison and Margaret Baird, married 2nd November 1800 in Falkirk, they are my
number one brickwall and have been for 30 years!!! Andrew died 19th July 1811 - his 3rd son, Andrew's christening says that he was the son of the 'late' Andrew Morrison.
Of their five children, I can only find Alexander's line. I believe - but cannot confirm - that their son William, born 17th April 1804, died in England (English death certificates of that time do not name the parent's names but I think it is him based on other information i.e. age, birthplace and SNP).
As for Mary Stirling's parents, yes, her parents were James Stirling and Elizabeth McIndoe BUT whether they are the JS and EM married 16th July 1801 in Killearn and consequently the daughter of Robert McIndoe and Bethia Duncan is unsubstantiated, yes, I believe this as do my modern day McIndoe and Duncan 'cousins' but I have never been able to put together a paper trail ....
James Stirling's provenance is unknown to me.
p.s. You said you didn't intend to go back any further, be careful, this stuff is addictive