The death of John Gray Esq of Birdston, at the advanced age of 78 years, occurred on 12 June 1820 and was announced in the August 1820 issue of the
Scots Magazine.
The
Inventory, Trust Disposition and Settlement and Additional Deeds of Settlement of John Gray of Birdston, father of Agnes Gray or Morison, were confirmed in Stirling Sheriff Court on 29 June 1836. You can download a copy of it at
www.scotlandspeople.gov.uk > Search the Records > Legal Records > Wills and Testaments at modest cost. This will make it clear whether it is a belated confirmation of John Gray who died in 1820, or refers to another John Gray of Birdston.
What might be more useful would be the sasine(s) recording his purchase of Birdston. These are not available online, so you would either have to go to General Register House in Edinburgh, or get someone to go on your behalf.
He could also be mentioned in other records that are not even catalogued online, for example the Registers of Deeds, also held in General Register House.
Searching the online catalogue of the National Records of Scotland for "Gray Birdston" produces just one result:
RH16/28 Graham of Birdston genealogy. (Gray-Buchanan Collection)There is a mention of Gray and Birdston in an article published in the Milngavie and Bearsden Herald on 11 May 1923. It says that he was a native of the district (New Kilpatrick), that his brother and sister-in-law died in America and he brought his niece and nephew back to Scotland. He made over the farm to his daughter and son-in-law, and his niece married David Muir, whose family had farmed Birdston before Gray bought it.
See also
https://www.rootschat.com/forum/index.php?topic=630508.msg6635476#msg6635476