Burke's Commoners

That's right. Not Burke's Peerage, but Burke's Commoners.

The following text is from "Burke's Commoners, Genealogical and Heraldic History of The Commoners of Great Britain And Ireland Enjoying Territorial Possessions or High Official Rank: But Uninvested With Heritable Honours." - published in 1837-8. I first searched the text on Ancestry, but it can also be viewed here through Google Books.

The work includes information about those persons who owned land or held high official rank, but were not considered nobility. Do note that Burke is not renowned for it's accuracy. One entry was of interest to the Keay family:

Graham, of Fintry.
Robert Graham , eleventh Laird of Fintry, who espoused, in 1735, Margaret , daughter of Sir William Murray , of Ochtertyre , by Catherine his wife, daughter of Hugh , tenth Lord Lovat , (By Amelia his wife, daughter of the Marquess of Athol , and grand-daughter of Charlotte de la Tremonille , the celebrated Countess of Derby, who so gallantly defended the Isle of Man against Cromwell . Her ladyship was grand-daughter of William, first Prince of Orange.) The 11th Laird of Fintry was succeeded by his son Robert.

Robert Graham , 12th of Fintry:
born 17 Jan 1749 , who married Margaret-Elizabeth, daughter of Thomas Mylne, esq. of Mylnefield , (by Isabella his wife, only daughter of Dr. George Gray, of Huntington , younger son of Gray, of Hackerton, a scion of the ennobled house of Gray ) and had issue;

Altogether 18 children (5 boys and 13 girls) are listed for the 12th Laird.

His first son, "Robert, was assassinated at Benares, by the treachery of a native chief, in 1799, aged twenty-four."

His third son, "Thomas (Captain R. N.) - married Maria, daughter of Admiral George Dundas, and died at Valparaiso, while in command of the Doris frigate, 09 Apr 1822."

Of particular interest to us was his 6th daughter, Elizabeth, of whom it is simply recorded that she "married James KEAY esq. of Snaigon, Perthshire." {Actually it was Snaigow.}

More on this James Keay later.

It is to be presumed that the Fintry referred to here is the Fintry in the Dundee area, but there is also a town of Fintry in the Stirling area, see a brief Wiki page here. Other sites which discuss the Grahams of Fintry include; this, this, and finally this in which we learn that the 12th Graham & Robert Burns were friends.

A quick google hinted to me that James Keay of Snaigo, Perthshire was an advocate in the year 1835.
An image here, and also here for Snaigow House, north of Caputh. I presume Snaigow is the estate which is now the family home of Viscount Chelsea, son & heir of Earl Cadogan (source: article in the London Evening Standard, and this page about their beef cattle).

It is recorded that the twelfth laird of Fintry died 10 Jan 1815, and was succeeded by his second son John:

The 13th Graham of Fintry was:

"John Graham , esq. thirteenth of Fintry, b. 24 Apr 1778, who entering the
army, at the age of sixteen, accompanied his regiment (the 90th) in the
expedition to Isle Dieu in 1795 . In 1797 he joined Lord Lynedock , then Col.
Graham , at that period with the Austrian army. Returning from that service, he
received the appointment of aid-de-camp to the Earl of Chatham , and proceeded
with his lordship, in 1799 , to the Helder. Subsequently, having raised one
hundred men for the 93rd Highlanders, he obtained a majority in the regiment,
and acted with it at the capture of the Cape of Good Hope in 1806 , where he
remained in command of the rifle corps until 1812 , when he returned to England
on leave of absence, and went with Lord Lynedock to Holland , in 1813 , as
aid-de-camp and private military secretary. In 1815 , he resumed his command at
the Cape, and was commandant of Simon's Town at the time of his decease, 17 Mar
1822 . He married 24 Jul 1812 , Johanna-Catharine , daughter of Rodolph Cloete , esq. of Westerford , Cape of Good Hope , and by her (who wedded secondly, in Nov 1826, Capt. Edward Danford , 49th regiment) had one son and three daughters."
{Grahamstown in South Africa was named after this man.}