I seem to have lost the photograph of the Currie, Thomson & Thom stone but here is the transcription.
"William Currie died 29th February 1875 aged 68 years. His wife Elizabeth Thomson died 17th October 1878 aged 71 years. Elizabeth Currie died 3rd April 1848 aged 5 years. Isabella Currie died 20th June 1853 aged 11 months. Their son John died 19th March 1927 aged 92 years, his wife Jane Thom died 24th January 1923 aged 78 years and their son William died 27th November 1880 aged 6 years".
Only the last 3 are mentioned in the Plot Book but it seems to be a very large plot so there are probably quite a few people interred there.
From the Day Book -
WILLIAM CURRIE, clothier, Cambusnethan. Aged 68 years, married.
Parents - William Currie & Isabella Paterson.
Interred in the old churchyard, 29th February 1876.
ELIZABETH CURRIE, housewife, Cambusnethan. Aged 71 years, widower.
Parents - William Thomson & Elizabeth Shearer.
Interred in the old churchyard, 19th October 1878.
Could the following two be William's sister and mother? There is an anomaly with the father's name, William/John but you could check that out.
ISABELLA CURRIE, housewife, Kirkmuirhill, Lesmahagow. Aged 87 years, widow.
Parents - Francis Paterson & Elizabeth Ure.
Interred in the old churchyard, 11th January 1870.
ELIZABETH McINTOSH, housewife, Lesmahagow. Aged 69 years, married.
Parents - John Currie & Isabella Paterson.
Interred in the old churchyard 26th August 1878.